I received the ProtoArc EM06 in exchange for a review here on Reddit. They do not have any editorial control over my review and did not request to see it before posting.
I'm a 3D animator and motion designer and I spend all day in 3D applications, After Effects, Illustrator and Photoshop. Years of furiously gripping a mouse (a Logitec MX Master) while working had resulted in quite a bit of hand pain.
3 years ago I bought my first trackball the ProtoArc EM03. The decision was based mostly on price if I'm honest. I found the shape, tilt and placement of the ball to be really comfortable. So comfortable in fact I bought a second one for my desk at work.
I had reservations about the EM06. I find the the horizontal tilt and shape of the EM03 to be really comfortable. While using the EM06 it took a while to get used to the tilt, or rather the lack of it. At first I found a little twinge of pain creep into my forearm, but it went away after a couple of days of heavy use. I think it was just my old body getting used to something new. The hand rest is a welcome addition and has a leather-like mat that is comfortable with out being squishy.
The scroll wheel and middle mouse button are *central* to my workflow (pun intended). This is probably my biggest sticking point with using the EM06. The scroll and middle mouse must be split into two buttons here. The EM06 is awesome about letting you assign all of buttons on the face of the device (and one on the side!). Having the scrolling and the middle mouse button split really messed with my head. 3D apps (Blender and Cinema4d) gave me the most trouble.
This isn't my biggest complaint about the scrolling. The scrolling is handled by holding down a button and rolling the ball. That works really well, and I actually prefer rolling the ball to the wheel as I can use multiple fingers on the ball to keep the scroll going. Also you are able to scroll in any direction which I find useful in a variety of apps. If you double click the scroll button rather than hold it, it will lock the EM06 into the scroll function. I can imagine this is useful while scrolling through long webpages or reviewing long documents, but for me, it sucks. Somehow I'm always double clicking it with out noticing and then I'm locked, unable to use any of the other functions of the trackball. This could be solved easily by offering a drag scroll function without the double click lock.
On of the EM06 biggest strengths is the ability to reassign just about every button. All 7 of the face buttons can be reassigned, along with the DPI button on the left-hand side of the body. I think this will allow almost any user to find a layout that will accommodate their usage. The functions on offer are quite a bit more than the usual mouse functions. I have a button that shows all apps which has eliminated a hot corner for me on the Mac.
Another huge plus is the ability to configure the buttons through a web browser. No additional software is required. This comes as a relief since I'm using this at work as well as at home, and installing additional software on my work computer isn't an option. I was also surprised to find that the configuration not only happens wirelessly (from the wireless dongle, not Bluetooth) but also happens instantly. As a long-time QMK user for my keyboard, I'm used to the wired, configure compile, restart dance. The webpage that has the configuration is barebones, but offers everything I would want.
Since I've moved into an office where there are about 30 people, all running multiple Bluetooth devices, I have become a dongle convert. The EM06 stores the dongle behind a small cover on the bottom of the device. Sadly the dongle is USB A. Understandable as USB C adoption still lags and users may not want to give up a precious C port for a pointing device. The trackball itself recharges via USB C. It comes with an A-to-C charging cable.
At 55 mm, the trackball itself is much larger than my previous EM03. It will come as no surprise that the bearings in the EM06 provide smoother roll than the plastic points of the EM03. I find the roll to be smooth and satisfying. It has become a habit to spin the ball and let it coast when thinking or idling at my computer. The bearings do make a little bit of noise, but they are mostly quiet with a thin hiss when spinning.
The EM06 features dual sensors for tracking the motion of the ball. I never had any tracking issues on the EM03 with its single sensor, but I'm guessing someone out there needs both.
The buttons are large and easy to press. I do find that reaching the top center buttons a little bit of a reach over the trackball. I use the center bottom button as my middle mouse button and it does cause me to curl my thumb into a bit of a claw.
I can't give you any exact numbers on the battery. I've used it for almost 2 weeks. Many days for 8+ hours and I haven't charged it once. It doesn't seem like the dongle reports back the battery life. Whatever the battery is, it's able to keep up with two sensors running for extended periods of time.
It comes with a case! The case has a custom insert to hold the EM06 secure. There is even a small round ridge on the inside of the lid to hold the trackball in place. The zipper is top notch and very smooth. I wouldn't have asked for a case, but given the price, you may not want to buy two. I've been using the case to carry in my bag on the train and it has been great. The only downside is the case is bulky. A small tradeoff to keep the device safe.
Overall, I can recommend the EM06. It's flexibility, simple setup and software free operation make it a great device for a lot of people. As a designer, there are some hurdles that you'll have to mentally overcome. The splitting of scrolling and middle mouse increased the learning curve in multiple programs.