I was wavering just a tiny bit on possibly switching to the X. But....one of my co-workers got the X today (his first Android phone) and needed me to help him learn to use it.
So, I got to play with the phone "in the wild" and not tethered to a display shelf in the Verizon store. I'm glad I got the opportunity to do so, because I am 100% set in my decision to keep my Fascinate now.
I didn't like stock touchwiz or stock motoblur. Launcher Pro feels noticeably faster on both phones than their stock UI. Unrooted and with stock settings there were places I noticed both phones lag.
I tested out the internet, my Fascinate was noticibly snappier (we both had full service and 3g at the time). I wasn't impressed with the widgets on the X.
I really didn't notice this. I thought both phones had snappy web browsers, whether using stock browser or the Dolphin HD browser. But coming from an Eris, I suppose anything would be an improvement!
But....the kicker? I could NOT leave the screen on my Fascinate. OMG, it is so much clearer and brighter. The screen on the X seemed almost smoky to me? The scrolling on the Fascinate seemed a lot smoother as well, but that could just be me.
You are right about the brighter and more contrasty screen on the Fascinate. Text is actually clearer on the Droid X, and clearer even on older phones like the Eris. Nature of the beast. TFT LCD vs SuperAMOLED. They each have strengths and weaknesses. I have good enough eyesight that I actually could see the screen patterns on the SuperAMOLED screen the first time I used it. The LCD screen on the Droid X has noticeably crisper and clearer text, and is a hair easier to read if you read a lot of eBooks. I only read on it a little, so no big deal. And after two days of usage, your eyes (and brain) seem to get accustomed to it. Doesn't bother me a bit now, and I most definitely appreciate the improved visibility in the sun, and the improved contrast when viewing photos or video. These advantages more than make up for losing a bit of crispness on the text.
Crisp, sharp letters do you no good if it's so bright you can't read your phone anyways!!
I am really, really loving the Fascinate the more I use it! And, I'm planning to root it in the near future (a big step for a non-techie like myself)! Don't worry, I have help.
I rooted the Droid X, got rid of all the bloat I could, installed AutoKiller, and installed touch pro. Felt like a brand new phone. Never slowed down one bit the whole week I used it, even loading it up with apps. AutoKiller has a truly dynamic and intelligent method of managing apps, services, processes, and memory usage, freeing up memory in the most efficient manner possible.
I also rooted the Fascinate (no one step out yet! ARGG!! My first foray into Android SDK was rooting my fascinate!! I gotta admit, I was a little intimidated by all the commands at first, but I took it step by step, and it worked. Wahoo!!!) I would totally understand if you waited for a one click option. I used the one-click on the Droid X. Beyond simple.
Now, after rooting the Fascinate, I also trashed some bloat, installed autokiller, and redownloaded my launcher pro. Substantially faster than stock. I haven't even done the one click lag fix yet. (don't want to give up 1GB of my memory!!!

) When they get the stable and accepted build of the lag fix down to 512mb I will be fine doing that one though.
I really didn't like the locked down UI's of moto's ninjablur, nor sammy's touchwiz. No thanks. Launcher pro is not only faster, but much more customizable. I recommend it on either phone.
The entire time I was helping my friend with his phone, he kept saying: "Why does your screen look so much better than mine?" He also liked the widgets better and the size/look of the phone in general.
I do miss motorola's resizable widgets. On top of that, I hate the stock weather/clock widget that comes with the Fascinate. WeatherBug FTL!! The size and look of the Fascinate are worlds more attractive and ergonomic than the droid x. The DX is robust and solid feeling, but it's not comfortable.
Want to know what else? All that extra bulk for a mechanical shutter, dual flashes, an extra 3 MP, and the Fascinate STILL takes better pictures than the Droid X, with or without the flash, in low light, etc. Not surprising though. Samsung has been making cameras for a long, long time, and they make some good compact sensors for sure.
Guess what? He's taking his X back and getting a Fascinate tomorrow!
**These are strictly MY opinions. I definitely see some great things about the X, I just prefer the Fascinate for myself. I'm finding it to be the perfect phone for me!! **
The X is awesome, robust, powerful, and impressive. No doubt about it. It's one of the best smartphones ever made, period. That thing got bars in places I didn't know you could get a signal, and boy was the call quality good, but I'm in your camp too, after using both side by side for some time now, in multiple environments.
The Samsung is just fitting my needs better. Let me explain a couple more of the little touches that win me over to the Samsung:
1. Puzzle lock screen: WOW this is cool. I was whining like the rest about no notification LED, but the puzzle lock screen more than makes up for it. No matter how much tweaking I did to the droid X, the screen unlock swipe was NEVER smooth for me. Everything else ran like butter after rooting, cleaning, and modding what I could, but not the stupid unlock swipe, whether live wallpaper or not. Not only is the puzzle screen smoother, but I can go right to where I left off, or I can go to texts if I got a text, or phone history if I missed a call. It's stock, works whether rooted or not, whether you have launcher pro or not, and it works smoothly. No lag at all. Live wallpapers play smoothly in the background the whole time. It's so impressive, and wows the crap out of everybody I show it to. Not only is it functional and responsive, but it has "cool factor" as well. Win!!
2. NO MORE POWER WIDGET!!! Sorry to shout, but that's how I feel! The power widget is integrated right into the notification dropdown screen. So flipping convenient. Again, it's a stock option, doesn't seem to lag the phone at all, and works regardless of root, launcher, etc. I love it. Saves me a whole row of space on my homescreens, too. I like keeping it down to three homescreens for speed and convenience anyways. This makes it four items easier.
3. I can change the volume of calls while the phone is pressed against my face. Maybe there's a setting on the Droid X, but I couldn't find it. I actually had to move the phone away from my ear while on a call in order to adjust the volume. It did this stock, and rooted. Very annoying. I've never had a phone I couldn't adjust the volume on while it was pressed against my ear. Moving it away means you're either interrupting the speaker, or going to miss a bit of what they say. The Samsung, like a "normal" phone lets me adjust away while it's right against my ear. Totally convenient. I know why Motorola disables the screen when it's pressed against your face. Same reason they all do. But why the buttons?? They're actually stiff buttons, and hard to accidentally press anyways ... just doesn't make sense.
4. Silence. The click of the Droid X buttons is mildly annoying to myself and my wife at night. Sometimes I'll play on the droid for a bit after the wife falls asleep. I hated the noisy buttons on the Droid X. The Samsung has silent touch buttons. I know you lose your great, accurate tactile feedback, and the feeling of defined buttons. But it's worth it to have silence!
Anyhow. those are just little things, and it is actually just a partial list, but those things combine to provide me with a much smoother experience with the Fascinate than the Droid X. Don't get me wrong. I love the CRAP out of the Droid X. It's amazing. I just like the Samsung even more, and it fits what I need it to fit and feels how I need it to feel noticeably better.