ProtoArc EM03 Review A Callback to a Classic, and Something New

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Protoarc EM03 on a tableThere’s usually not one best <thing>. That doesn’t stop techies from going a little crazy trying to figure out what the best <thing> is for them. From keyboards to mice, game consoles to operating systems, the tech-obsessed never seem to be happy with what they have, and need to see if there’s something better.

I am among the worst of them.

When I was first introduced to the wonderful world of trackballs, I tried two thumb-operated trackballs, landing on the Elecom EX-G Pro. I modified it to make it smoother, but, of course, I wasn’t done. I needed a trackball for travel, so I picked up a Bitra, I wanted an accurate finger-operated trackball so I picked up a Kensington Slimblade, and then I was interested in other types of finger-operated trackballs. Many, traditionally, have taken inspiration from the Microsoft Trackball Explorer (MTE). The MTE has gained a cult following in the trackball community, and, as such, has had its share of imitators. The more ergonomic shape combines the tilt of a more ergonomic mouse with the finger-operated trackball orientation many prefer. Of course, I had to try one of those.

Today, I’m taking a look at the ProtoArc EM03. It’s a propriety design, but one that takes heavy inspiration from one of the trackball greats, the MTE. I don’t have an MTE to compare it to, as those can go for as much as $500 new, $80 used. However, I can compare it to other trackballs that I have used, and make an objective review of how it is to use.

After using it, I bought another similar style trackball, though not because I didn’t like this, but because it made me realize I could love trackballs with this form factor.

In This Article:

Comfort and General Usage

Protoarc EM03 side buttonAny time there’s an ergonomic mouse that your hand rests on, the creators have to make a choice. How big is the hand we’re designing for? In my experience, the answer is, “Smaller than average hands.” Because every tech reviewer seems to say the same thing about these things, that they believe it was designed for a smaller hand. I’m a certified large hand haver. Usually medium or large in women’s sizing, depending on the glove. So take that into consideration when I say:

I believe it was designed for a smaller hand.

See, if I rest the heel of my palm towards the back, it doesn’t quite reach a sort of “hump” in the middle, where it could nestle in. However, my fingers easily reach the ball and buttons. However, if I move my hand up where it seems to be guiding my palm, there’s a ton of overhang. I so rarely feel like these are made for my hand.

All of that aside, this isn’t too bad, although I did find that, because of the hand size, my wrist is held at a more flat angle. I can rectify this my mostly resting it on the hump, but I had another solution: a padded slanted mouse pad I found on Amazon. This elevates the rear of the trackball, putting it at a downward slope of about 8º. This angle, I have found, is far more comfortable.

Outside of sizing issues, the rest is largely praise. The primary click button has a nice gentle slope to it that rests your thumb nicely, buttons are easy to press with the exception of the mouse wheel, and the ball is large and exposed. Often these kinds of setups will cover more of the ball so it doesn’t fall out if you invert the mouse. But this gives you a large surface to use with a variety of fingers. I do wish the middle click was a little easier to press, but outside of that, it’s largely very well done.

Smooth and Quiet

Closeup of the front of the protoarc EM03 showing the forward, back, scroll wheel, and main mouse buttonsFresh out of the box, the trackball was smooth. For some trackballs I’ve used, there’s a break-in period, especially those from Elecom. This was perfect right away. There is some stiction, but the ceramic bearings outperform ruby bearings right away. This reminded me more of my Kensington Slimblade Pro than my less expensive trackballs. As it is my least expensive trackball to date, that’s incredibly impressive. I haven’t swapped the bearings on this. I may not ever have to.

The primary and secondary click buttons have a quiet click, perfect for office use. Even the scroll wheel has just a light notchiness to it, keeping itself quiet as you scroll. The back and forward, as well as the clicking scroll wheel, however, are firmer, louder clicks. This usually isn’t an issue, but I do wish the scroll wheel was easier to click. I find I sometimes accidentally spin the wheel slightly when I don’t mean to as a result of how hard it is to press.

Customization

This mouse has five buttons. I wish it had more. One or two more, perhaps placed around the trackball area, would have made customization easier. Still, thanks to Steermouse, I was able to add different chords for various functions, giving me many more functions than those five buttons could initially do, like Mission Control, switching spaces, engaging a trackball scrolling mode, and more. I do wish this had more buttons like the Deft Pro, but it does have just enough to get by.

This particular model also has RGB lighting, but you won’t really notice it. It’s angled away a decent amount and not overly bright. Still, it’s another layer of customization you can play with if you’d like.

Speaking of secret layers of customization, you might not be able to tell, but you can change the DPI on this trackball. I forgot how to do it for this review and had to clean off my entire desk to find the user manual. So, okay, maybe that’s a positive. I certainly needed a cleaner desk. To change the DPI, you hold the scroll wheel mouse button and the rightmost button for 5 seconds to switch. There are four DPI levels, 200, 400, 1,200, and 1,600. You’ll cycle through them in order. So, if you’re trying them all out, it’ll take at least 20 seconds to figure out which one you want. Once you do, you probably won’t want to change it.

Finally, you can connect via wired, Bluetooth, or a wireless dongle. And yes, the dongle can be stored inside the mouse too, so you won’t lose it.

Battery Life

I almost never have to think about battery life with this. It can last weeks on a charge. You can charge it via USB-C, and, unlike mice made by Apple, you can charge it while using it. The reported battery life in the Bluetooth menu isn’t very accurate, but in the weeks I’ve been testing it, I’ve only had to charge it once so far.

Other Notes

Protoarc EM03 and the USB-C portAny time I use a device with soft touch plastic like this, plastic that just kind of feels a little soft, I always think of my other electronics like that. I have a few different devices that I don’t even like to touch anymore because the soft touch texture eventually became slimy. This is due to plastic breaking down slightly, and can happen even when you store a device in a drawer. Something that touches your hand’s oils or lotions all day could break down faster. You can kind of polish it a little with a solvent, but it’ll always be a mess. The EM03 has a bit of that soft touch feel, and I worry that down the road, it could become a gunky mess. Perhaps, if I remember in 5+ years, I’ll update this post to say whether or not it got gross.

I don’t often talk about gaming with mice because most of my gaming is done on a console. However, I did recently load up a few games on my Mac and found I vastly prefer this style of trackball to a thumb-controlled trackball for gaming. The large trackball surface and the amount of it that’s exposed make this a great trackball to also use for gaming. Though I can’t say whether or not you’ll perform as well. That’ll be up to you to practice and find out!

Overall

ProtoArc EM03 with a keyboard for scale. It's actually quite large, being taller than an HHKB-layout keyboard (no function row)The ProtoArc EM03 surprised me. It’s under $40, currently $32.99 on Amazon as of this writing, and feels like it could compete with trackballs that cost more. There are pros and cons with this versus a similar trackball I have, the Deft Pro. This doesn’t have as many buttons, but it exposes the ball more for better gaming and larger movements. It’s relatively comfortable to use, has excellent battery life, nice soft-touch buttons, and the trackball is smooth. In so many ways, it exceeds what I was expecting for a “cheaper” trackball. I was not expecting it to be in leagues with the more expensive trackballs in my collection. This is an excellent value.

Due to its price and surprisingly great quality, I could see this being a fine first trackball for someone thinking of getting one. While most normal mouse users feel comfortable switching to a thumb trackball first, it’s hard to deny that this would likely be a more versatile first choice. It may not feel as premium as some other trackballs I’ve used, but it can certainly hold its own for a fraction of the price. Definitely worth checking out if you’re thinking of getting a first trackball or perhaps your first finger-operated trackball. This isn’t a bad choice even for more experienced trackball users. ProtoArc did a great job making a MTE-like trackball that doesn’t break the bank.