I have played the demo of the first game, very interesting and great game, I find. There's a demo out for book 1, if you're interested to see how you like it.
Apart from other games, pciking a character atually means something; rogues do have more ability to unlock chests and stuff than fighters etc. have. Its gameplay mechanic are similar to the old Baldur's Gate games - but its not copycatted either, however.