I don’t have one but for some reason they’re very popular with my twelve year old daughter and all her mates (think they like the BBM for organising riots etc!) Anyway hers is currently back under warranty for the second time in six months with the same fault (track-pad thingy not working) this seems to be very common and alot of her friends have experienced the same thing. To be fair they are using them all the bloody time* but given this obvious design/hardware fault I would avoid personally.
*Whatever happened to playing in the park, jumpers for goalposts etc. Kids today, I dunno, moan, moan, grumble, grumble etc, etc. 😉