I'm giving MobileMe another go. I signed up when I got my Mac a couple of years ago, but didn't renew it after the first year, as I wasn't really using it that much.
The main reason I'm trying it out is that I've got bored waiting for Gmail Push email to work correctly on the iPhone. It's flakey at best, and plain not working most of the time. Working away from home, having Push email on my iPhone is pretty important to me. I know I can use ordinary IMAP access, but I like having the messages sitting there in my Inbox waiting for me to read them, rather than having to wait for them to load. I'm impatient like that.
First impressions (I've only been using it for the past 24 hours) are very favourable. Push is very fast and, so far at least, very reliable, so it's already serving it's main purpose.
I've also decided to try and use more of my native Mac applications - Mail, iPhoto, Safari etc - and MobileMe plays very nicely with them all, as you'd expect.
I had a quick play with uploading photo's from the 3GS to my MobileMe account and it's oh so very easy, as is video.
I'm starting to feel that maybe I didn't give it a fair chance the first time around (perhaps because I was still used to the Windows way of things), so I'm going to persist with it for a month (all my mail is still going to Gmail, then getting forwarded to MobileMe, so it's all still there if I decide to go back) and see how I feel about it from there. I've gone the whole hog. I've disabled all Google synching and will rely completely on MobileMe for the duration of the test.
One nice side affect that I hadn't anticipated is that battery life on the iPhone seems substantially better. Maybe because Gmail Push was constantly trying to sync but failing?
I'll let you know how I get on during the experiment.