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!

The mouse keeps losing connection.

Uses Kensington's trackballs, which cost as much as this, but Kensington has significantly better quality. This, however, has a thumb-ball which I think is more comfortable. Like all trackballs I tested this works for easier everyday tasks, but should you draw in CAD or anything that requires...

It has Bluetooth and an adjustable base.

The ball is difficult to remove for cleaning.

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 :)

I have a bit or carpal tunnel trouble and I find this the best thing on the market as my hand and arm can stay in a relaxed natural position.

Have had one of these at the office for a number of years now and it has made such a difference to wrist soreness (I don't get any anymore). With the recent move to doing more work from home I purchased another one for home.

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!