I have this one. I hate it with a passion, owned the v1 before (the one that came with a hub). The problem with this one, is that it comes with a small USB dongle that you plug in directly into the USB port. For some reason, I'm assuming some sort of interference, it never works properly when plugged into the USB ports in the back of my PC. In this scenario, it suffers from extreme lag and erratic behaviour. I had to rewire the USB ports and move them to the top of my case. It's been working more or less fine when used in this manner, however it does still suffer from occasional lag and what is much more annoying, occasional disconnects (especially the media pad, it keeps on constantly disconnecting and sometimes won't reconnect).
The bottom line, from my experience, I'd avoid it like the plague and go with the previous model, which was much more reliable.
Having said that, this is just what I've experienced, your mileage may vary.