Summary: I would say it's piece of shit. I owned/used many in my my 20 years or so of using a computer, but this one is really bad, because sometimes it stops functioning and moves REALLY slow (with new batteries) and the build quality feels like cheap plastic. I would say it has a nice hand grip, but another thing that it lacks is that the wheel can't move side-ways, only vertically.
Summary: Just bought this mouse and it jumps around and freezes a lot. It's a terrible mouse. I thought that maybe I just needed to replace the batteries. YOU CAN'T REPLACE THE BATTERIES! It says 30 month battery life on the box. I guess they just expect you to buy a new mouse by then.
Summary: The outstanding battery life isn't a plus point when it's achieved by sending the mouse to sleep almost as soon as you take your hand off it, and then not polling for wake-ups very often. Neither is this a very comfortable mouse, with the scroll wheel feeling a bit awkward and not grippy enough. It does have a clicker, but it still doesn't feel like you can confidently cycle through weapons in an FPS or through Minecraft's hotbar.
Summary: I have a HP TouchSmart desktop computer, and the wireless mouse that came with the computer stopped working properly (the left mouse click stopped responding). I therefore bought a new wireless mouse, choosing a HP one, thinking that it might be compatible with the dongle I already have (and which was supplied by HP).