Pros: The trackball can rest either flat (like the M570) or at a 20 degree tilt. The latter is actually slightly more comfortable. The tracking is as good as the M570. I haven't gotten used to the precision tracking (the button next to the thumb rest controls it). Finally, bluetooth compatibility. One issue though, you need a second mouse to configure the bluetooth. Also, finally a rechargable mouse (although the battery life on the old M570s was very good).

Cons: I'm not sure why they made the bluetooth/2.4Mhz switch is on the top. It is usually a configure once an forget it. A hardware rather than software switch on the bottom (better labeled) would have made more sense. Except for the high precision button, the buttons are compatable with the M570, so no upgrade there.

Overall Review: I've gone through a large number of M570 trackballs. This looks like a good upgrade. I'll see if the new arm angle helps my tendonitis.

Pros: The two additional buttons are a nice edition. Unfortunately, they are placed in such a way that it is hard to move the mouse by picking it up by the edges. I had no connectivity issues with the mouse in either 2.4 GHz or bluetooth mode.

Cons: There is too much friction between the ball and the beads on which the ball rests. In particular, this means a fair amount of pressure is needed before the ball will start to roll, this makes fine movements difficult. In particular, it gives too much hysteresis when trying to use the mouse.

Overall Review: I'm used to a Logitech M570 trackball. The increased friction just made this trackball a little bit too difficult to use. I hope that the manufacturers can improve this, as otherwise it seems like a good mouse.

Pros: Did connect to Linux box (Ubuntu 20.10) without apparent issue.

Cons: There is no version of the configuration tool for linux and tech support cannot give me any information about tools which can be used to configure this drive (i.e., set RAID 1) with Linux.

Overall Review: Would not consider this drive for use with a Linux system.

Overall Review: Check the dimension carefully. The length of this card is 11.75" and it simply did not fit in my case, which only had about 10" of clearance.