I have 3 tablets, the iPad, the Transformer and the Playbook. Seems like I always end up using my iPad and the others just sit. I don't know why, but I always just gravitate to the iPad. Maybe it's because I had it first and I am just use to it.
I will say the OS on the Playbook is the best, but the screen is too small. There is also noooooo aps for playbook and you need a Blackberry phone for it to be really useful because there is no native email or calender.
I have not spent that much time with the transformer. Maybe I will play with it this week and report back later.