The nail in the coffin came from Walt Mossberg (a.k.a. Uncle Walt) on the Wall Street Journal. His article on MobileMe is probably the worst review I ever seen him writing (and he writes a lot...). The title: "Apple's MobileMe Is Far Too Flawed To Be Reliable". Ouch!
The rest is worst:
[..] Unfortunately, after a week of intense testing of the service, I can't recommend it, at least not in its current state. It's a great idea, but, as of now, MobileMe has too many flaws to keep its promises.Ooopss. I share with Walt that it is a great idea. Even better if you could use more than just an iPhone for it or more than just an @me.com account... A great idea of a service everyone would use, and even pay for. Unfortunately, it is not easy to make it happen. You need lots of time and lots of people that test and make sure the solution really works. It is called open source. Steve, give us a call, we'll come to rescue you :-))
I am not referring to the launch glitches that plagued MobileMe earlier this month, such as servers that couldn't keep up with the traffic and email outages that, for some users, persist as I write this. Those were bad, but they have eased considerably. Apple already has apologized for them and is giving customers an extra 30 days on their subscriptions to make up for the poor start. The problems I am citing are systemic. [..]
But in my tests, using two Macs, two Dell computers and two iPhones, I ran into problem after problem. One big issue is that while changes made on the Web site or the iPhone are instantly pushed to the computers, changes made on computers are only synced every 15 minutes, at best. Apple has admitted that this is a problem, and says it is working on it.
But there's more. The Web site was sluggish, and occasionally calendar entries wouldn't load at all. Sometimes, you have to manually refresh the Web pages to see changes made on your devices. And when I tried to open my Web-based file-storage page directly from the MobileMe control panel on Windows, I got an error message on both Dells.
My MobileMe calendar, which originated on a Mac, didn't flow into the main Outlook calendar, but appeared as a separate calendar in Outlook, which was visible only by changing settings. My address-book groups on the Mac, which are simply distribution lists, didn't show up as distribution lists in Outlook, but as separate address books, and they also weren't immediately visible. Apple blames Outlook quirks for these issues, but in my view, it should have overcome them.
Other problems abounded. On one occasion, my synced contacts on the iPhone appeared as names only, without any information. In general, synced contacts on the iPhone loaded slowly.
When my Apple Mail program used rules I had set up to automatically file certain emails into local folders instead of leaving them in the inbox, they simply disappeared from my MobileMe account on the iPhone and the Web site. Avoiding this requires a tedious editing of all your rules.
Twice, MobileMe was unable to sync my bookmarks at all, and when it did, their order was scrambled. When I synced contacts to my iPhone, my custom ringtones for particular contacts were lost and had to be reselected.