Disclosure: Ive used LogiTech trackballs since the early 1990s (they were a different sort of beast back then, wired and pretty much an uncontoured little box with a ball on top); this is my third by that company (which give you an idea of how reliable they are Ive switched to new units twice but...

I use a track ball for over 10 years. This model does let me adjust the ball movement, either is too fast or too slow. Also it does not let me pick a field and move it elsewhere in excel. The other mouses with a ball work fine. But not this one. I am still using it. I will see in the future.

I bought this to help combat the strains of using a mouse at work every day and I have to say, it did not disappoint. I bought the cheaper Logitech mouse a few months ago and found it awkward and not really usefull at all so thought I'd try it's bigger (but more expensive) brother.

very nice mouse, extremely function certainly a niche technology - personally enjoy the functionality for design work

I recently bought this after my faithful m570 stopped and it's brilliant, couldn't go back to a mouse and I love how it's rechargeable and easy to use and fits in hand nicely

I have always enjoyed ergonomic mouses. I was super skeptical about purchasing this mouse because it was wireless and didn't look comfortable. my partner convinced me to get it. I am so glad that I did. It's super comfortable and love the precision mouse mode for more detailed movements.

Fully featured, having programmable back and forward navigation buttons, as well as programmable left and right clicks on the scroll wheel. The comfort factor of being able to customize the angle of the mouse cannot be understated.

Great upgrade from the logitech m570

If you struggle with pain and discomfort after using a mouse all day, then get this one. It takes some getting used to but it's worth the minor inconvenience and the price tag. I've never felt so comfortable using a mouse!

I have used a Logitech trackball for decades and I like this 1 the best (this was bought to replace the Ergo I already have). I have a decent sized bedroom with my computer and bed in opposite corners. The Ergo works from the bed :) to be fair it works on the computer side of the bed but not on the other side. The only thing that concerns me is the the long term battery life – when new (about 3 yrs ago) fully charged it would last the full 4 months plus, now its about a month and takes ages to recharge (can be used while charging). Given the price I would expect the battery to last a couple more years before starting to die. Bottom line – would still buy again :)