ProtoArc Vertical Wireless Trackball Mouse, EM05 NL Bluetooth Ergonomic Rollerball Mouse Rechargeable Computer Laptop Thumb Mice, 3 Device Connection, Compatible with iPad, Mac, Windows, PC-Gray

Basic description: essentially the trackball equivalent of the "vertical mouse."What do I think about it:Excellent.Ergonomic design is fantastic for me. Helps my shoulder vs. other trackballs because the angle of the arm impacts which muscles in the shoulder get used. It's just a comfortable, natural angle that allows my arm to be more relaxed while having good control of the cursor.This is also a much better value than the extra ergonomic Logi[tech] equivalent, which is nearly 2x the cost as I type this. And by the way, you'd have to use the cushion thing the Logi unit comes with to achieve a similar angle. Maybe it's great/fine, but if you want the steeper angle then why have a 2-piece design?Other aspects: Buttons somehow feel crisp while also being quiet. Effort feels just right to me. Weighting of the ball feels just right and it moves very smoothly. Scroll wheel could feel a tad tighter for my liking but this is being very picky; it behaves as I expect/want.Subjectively, the ProtoArc feels higher quality than the Logi M575 I'm coming from. The M575 doesn't feel cheap to me, but this feels nicer/higher end.If you like switching between DPI levels on the fly, there's a button on the mouse for this. I don't use this but the button is not in the way.My only open questions about this unit is how the Li-ion battery and buttons will hold up. The Logi units use plain old AA batteries, which makes them a non-issue to replace (though less convenient than Li-ion in some ways). The buttons fail on Logi units faster than I think they should. Time will tell here but I'm hopeful given that ProtoArc put the time and effort into creating a very thoughtful product.

Love this trackball mouse. Ball motion is smooth, quiet, and well-constrained. Button clicks are not as tactile or audible as a normal mouse, but that's fine. Scroll wheel is well-weighted and doesn't feel cheap. Forward and back buttons are placed in a great location and are tactile. USB-C charging is a nice touch. The ability to switch between a paired receiver and 2 other Bluetooth-enabled devices is what set this one apart for me. This one has served me well both in the office and at home.My only gripe is I'd like to have the device switching button located on a finger-accessible part of the body to switch devices faster. I use this to jump between PCs and a RasPi, so lifting it up to swap back and forth can be tedious.

Review is being written after a month of use and with years of familiarity with similar mice.Priced well for this style of mouse. Easy to adapt to if you are already familiar with trackball mice (like logitech's). I appreciate the extra buttons. DPI button does not have AS much fidelity as I would prefer, I definitely have to adjust my devices more than I'd like in addition. Battery lasts a very good long while, even with regular-to-constant active use. I love the connection to multiple devices. The mouse does not slip around on the desk with use.My biggest con is that the trackball movement is not smooth. It's a little jumpy and is not suited to accuracy. When moving the cursor slowly, the trackball sticks slightly and makes little jumps. Extremely frustrating for use in FPS gaming. Would strongly recommend Logitech's marble mouse over this one for that. The same issue is present when working at a fast pace & accuracy. I am constantly miss-clicking while navigating programs like the office suite of products. I'm not certain that this will reduce with practice.If you are used to standard wrist-motion laser mice, you honestly might not even notice the trackball accuracy issue, at least when it comes to point and click/non-FPS use.Would like to see the trackball issue resolved before considering sticking with the ProtoArc mouse.

Price and use of this ProtoArc Vertical Wireless Trackball Mouse are amazing. Very comfortable to use during long hours. Works wonderfully on PC with a wireless fob and on iPad with Bluetooth. So easy to use that my wrist is at a more natural angle. I’ve been using trackballs for close to 20 years, with different brands and styles, and this one has topped them all with the angle, button placement, and thumb control!

Strong connectionLong lasting battery lifeComfortable to use and accurateknocked the Logitech Ergo MX advanced plus max off its perch as my most used input device. In my real world use, it seemed to have better battery life, was just as accurate and easy to use, but with the MX, it had that adjustable base and I alwasy had a peoblem with the base flipping over, needing to be adjusted back into position. With this I dont.

It is a very beautiful device and very nicely packaged. However, I found it very difficult to use. I was not able to adjust the cursor movement: It was either jumping around my three screens or creeping along. It may be that I needed time to get accustomed to the device but it felt a bit wonky for work.