I used the bash my friend's iPhone all the time. ("Go ahead and copy/paste that into an MMS and send it over to me.") I have an HTC XV6800 with Verizon, and I'm very satisfied with it, but he kept showing me all the cool stuff it could do, and I ended up getting one on his family plan so I didn't have to pay for a full plan. It is definitely an awesome phone, but I can't depend on it completely. It can't do the synchronization OTA of my Hotmail contacts, nor sync with the Outlook running Outlook Connector. Also, the AT&T coverage is just not up to par with Verizon, nor the data speeds. So if you don't depend on Windows Live as much as I do, or don't do a lot of business intensive stuff that a Blackberry or Windows Mobile phone can handle better, then go for the iPhone. It can do a lot of things a Windows Mobile phone can't, but there are still some very basic things it still can't do (until the OS 3.0 update).
So I basically have 2 phones, one for business, one for pleasure.