I am coming from a blackberry 8800 and have used most smartphones on the market in recent history. While there obviously need to be some tweaks to the mail app, I don't feel the need to go back to my blackberry. Gmail functions the same(just a bit slower on notification) as on my 8800 and my .mac is working great. The one issue I had was setting up my work via pop3, but once I found the correct port I was golden. My biggest things is the ability to see the different inboxes so I know where the new messages are..and the ability to set different notifications for each. It took RIM a while to turn the blackberry into the premier email device yet it still has shortcomings. I am confident apple will update the functionality on the iphone so I am willing to be patient. My iphone email has given me fewer headaches than any windows mobile device I have used
Besides I really am starting to like the keyboard and I am already as fast on this as I was my 8800. I won't even mention how my poor 8800 looks and feels outdated after using iphone.