Guess what? I just bought a V500 today and I LOVE IT ! It is pretty small so you may wanna check it out and see if it will be a problem for you.
To me the response is the same as using a corded mouse. Some people reported problems with the sensitivity settings going back to being very sensitive whenever you restart or reconnect the mouse. I had the same problem, but uninstalling LCC a restart, then reinstalling it seemed to solve the problem. I almost paid $20 for USB overdrive just to be able to keep the sensitivity settings. And overdrive allows you to set it to scroll faster horizontally, the LCC scrolls slowly horizontally. But I decided that $20 wasn't worth it.
I also got xGestures from the recommendation by someone else in this forum. OMG it makes up for all the missing buttons I am missing from my mx510 (too big for me cause my wrist to hurt).
Another thing that I'd really want to add is that the pads at the bottom make the mouse so damn smooth! And the weight to it is nice, making it feel well built, unlike the light cheap feeling mx510 I have which isn't as smooth on the same surface. Maybe because the pads are new I am not sure, but that was the first thing I noticed when I started using it.
Ever get tired of scrolling through long pages with the wheel? I do, especially when I am coding and the page is SUPER long. This thing is great, as now I just put my fingers at the edge (depending whether you want to scroll up or down) and press it down in the direction desired and hold. The page will keep scrolling until you let go. If you just want to scroll normally, just move your finger like you will when you use a wheel.
I am a very happy person today !
Hope this helps you! And sorry for the long post.