I agree, MMS support is quite bad. SwirlyMMS solves some of the problem, but you still need an additional app just to explore the folder where images are downloaded to.
Otherwise, i am very pleased with the iphone usability. There are lots of people saying that it's not worth the money and that they can get a device with better specs for less money, but in my opinion the main thing about the iphone and Mac computers in general are not just tech specs but the user experience. I've had a chance to play with quite a few gadgets with both Windows mobile and Symbian, but to me their user interface (design, menu structure, smoothness...) didn't come close to the iphone.