I personally love this phone, but I do acknowledge that there are issues(some minor/some not) with it.
Pros:
Screen quality is beautiful - Put in some HQ MV or animation on your video/gallery and be amazed at the color quality.
Relatively quick - Although I don't have a long line of smart phones under my belt, I have done research and played with many of my friend's wide variety of smart phones so I feel pretty comfortable in saying that the Fascinate can hold its own compared to other smart phones. I do occasionally have a giant 'lag spike' where it'll take a good 2 seconds or so to exit/access an app, but those are rare. Haven't really been able to locate why that happens.
Screen size is 4" - Now to some 4 might be too small or too big. I personally was leaning towards the X but the screen was too big. Now the Inc screen wasn't exactly small but it felt a bit lackluster considering that the phone is a bit aged, has terrible battery life for its screen/speed that really isn't any better than the competition.
It's light - Now this might be a con for some considering that lightness gives a feel of fragility, but I love this phone's weight. It's also pretty durable considering that the entire front of the phone is encased in Gorilla glass.
Cons:
Bing - But I usually see this complaint as something relatively minor considering that Androids became so popular because of its ease of customization. If you're really gungho about a stock purchased phone then you would be a mindless I-phone drone.
Droid X is faster - I don't argue this, and if you're a pure numbers guy the Fascinate actually doesn't compare. However even side by side(friend's X) I really can't tell any difference in performance.
Call quality - there is a bit of static or 'echo' whenever you make a call. I'm more of a speaker/messaging guy so I can get over it, but if you're the type that makes long by-the-ear phone calls you'll probably get annoyed by the robotic back-voice you'll hear as you talk.
GPS - I'm not even a huge GPS user but this phone fails miserably on this for me. I've been driving comfortably without a navi or w/e for 5 years so I'm quite comfortable with my knowledge of the local streets, but the fact is that if I ever needed GPS it's pretty damn near useless.
Battery - Now this is something you can only really experience by actually taking a phone on a test drive, however I found my battery life to be a bit lack-luster. I've read people saying that they were able to go two-three days with moderate use, however I've never even come close to that in my month of owning the phone. It's still no Inc in terms of bad batter life, but it still feels a bit sub-standard to the point where I honestly feel like I need a car charger.
Hope this helps in anyone thinking about switching. The phone is in my opinion a great phone. But there are quirks, and if any of the cons I mentioned are a major turn off for you(except bing if you're even a tiny bit tech savvy), you should look into other areas for a phone.