I'm also coming to the Fascinate from the Storm 2.
Email on this phone *should* "actually work" but it sure didn't when I first got the phone. I almost took it back because the stock email app would work fine for a while then for no apparent reason would stop checking for new POP messages. I switched to the K-9 email app and that took care of that issue. Email sync was one of the issues listed in the maintenance release that came out a few days ago, but I haven't tried the stock app yet to see if it works right now. I think I do like the stock email app a little better than K-9 aside from the sync issue.
In the beginning I had a lot of problems with the connection bouncing between 1x and 3G. At times the Mobile Hotspot was completely unusable because of this. The bouncing between 1x and 3G seems improved after the update.
I might miss the notification LED. It is nice to have in meetings when I have the phone silenced. I might have to install NoLED for that.
I thought the Storm2 had an awesome GPS receiver, very fast and worked indoors in most structures. The Fascinate's GPS needs a workaround to get it started, which takes a long time even with the workaround, and does not seem as effective indoors.
In a previous thread I commented about battery life and charging time. The Storm 2 was a clear winner there for me.
I'm also finding that I was pretty spoiled by Blackberry's automatic text replacement and conversion features.
But, aside from these gripes, I am pretty happy with the Fascinate. I'm getting pretty good at Swype, and I'm getting used to a lot of the other things that are different. I'm realizing that there are reasonable tradeoffs, like, if I want to have an incredibly fast mobile web browser I'm going to have to lower my battery life expectations a bit, etc. After a week with the Fascinate I dot think there's any way I could go back to using the Storm2.
Jack