Mytouch VS iPhone

My boyfriend is planning to open a phone line and he wants to get the family plan because it'd be cheaper a little and since I already have AT&T, I don't want us to get AT&T again. I want us to get T-Mobile because it'd be convenient cause most of my friends are T-Mobile anyway but I want the iPhone 4g I like it because I have the iPhone 3gs and it's pretty good however the iPhone 4g has lots of bugs if it's unlocked for T-Mobile. My friends have the Mytouch by Android, HTC and they said it's really good but what do you think? What are the pros and cons with Mytouch VS iPhone??