Hi all, wanted to seek some opinion from HP 512 users. I have been eyeing a couple of PDA phones now, my options currently are O2 XDA Atom and HP 512. My questions are :

1. Is HP 512 as good as a full-blown PDA phone like O2 ?
2. What are some of the things that O2 can do that HP 512 can't do ?
3. Is there any feature in Windows Mobile that is not available in HP 512 ?

Actually my mind was set to get the O2, but after seeing HP 512 I'm beginning to have second thoughts... Thanks.