MobileMe would be great if it actually, you know, worked.
For me, MobileMe has been a fucking disaster. First, during the first few days I had ENDLESS contact/calendar conflicts, and MobileMe actually deleted a random set of about 100 contacts.
That's all settled down now, but now iDisk has become so unreliable that it's almost pointless. If I don't explicitly sync up a computer, and then check that something made it up to the server (via the web UI), then get on the other client computer, and push the sync button, and sometimes reboot, and push the sync button a few more times, nothing syncs. This is despite the fact that everything is set to "Automatically" synchronize.
Guess what? Copying stuff to my personal web site and manually copying it back down is less of a hassle. And I'm paying for this? Bleah.