Thats a pretty good question. I've spent some time with all three and its a little bit hard to say which is better between touch pro2 and iphone, because the features on the touch are outstanding.
But, the iphone does surpass most phones on the market.
Its simple: if you dont want to spend a lot of money but still want a really good phone with plenty of features, you would have to get the touch pro 2. If you want a phone thats fun to use for multimedia purposes, get the Iphone.
If it was me I would probably get the iphone, because its a fun phone.
<------------------Hope this helps------------>