I'm trying to decide between the EVO, Galaxy S Pro, and Droid X. Samsung's press event is Tuesday and hopefully we'll gain some information about the Galaxy S variant coming to Sprint.
Droid X -> Verizon
You couldn't pay me to leave Sprint for Verizon, but your mileage may vary.
While the Droid X is getting a reputation for out-benchmarking the Snapdragon processors (EVO, others), I flatly dispute it - see my link posted above,
I call shenanigans!
I'm looking to upgrade from my no longer needed Nextel ancient Blackberry Curve to a current high end smart phone.
Personally, I don't think you could wrong with any of the choices on your short list - just in case you wanted any second opinions.
Samsung's Galaxy S Pro To Be Sprint's Second 4G Phone?
Sprint’s Samsung Galaxy S Pro gets detailed - SlashGear
The Galaxy S uses the Samsung S5PC110 (Hummingbird) processor. Its GPU is a PowerVR SGX540.
That's way above the Droid X's OMAP 3630 or EVO Snapdragon 8650.
That GSPro looks like it's gonna be one helluva phone.
If you have time, you could also wait for whatever's going to made with the Snapdragon 8672 - 1.5 GHz, dual-CPU - and oh yeah, 1080p video capable.
Qualcomm News and Events - Press Releases - Qualcomm Ships First Dual-CPU Snapdragon Chipset
FWIW - I went from an Ocean (feature phone, dual slider QWERTY - actually, a great phone for what it was), to a Samsung Moment (slide out QWERTY), to an EVO.
I mention that because work had me all set up to go with a BlackBerry, but I took a left turn to the Ocean, and found I could really fly on a decent slide-out keyboard. The Moment, by the way, was a step down in that department - a big one.
I was finding myself typing on glass more and more because I didn't like the Sammy keyboard at all, so I decided to risk going with the EVO.
For some reason, most people don't like its built-in keyboard, but I do, and find it's a breeze - and with Android you can always swap that out for whatever.
Anyway, I don't know what your experience or background level is at all, not trying to be patronizing, just thought I'd toss those impressions out there given that you mentioned you're still living with a Curve and don't know if you have any doubts about typing on glass only.
BTW - this is probably obvious - get a GMail account if you don't already have one, and play around with backing up your contacts to Google Contact at the GMail website. Do that ahead of time for your foolproof protection before changing platforms. Everyone has their experiences getting into Exchange on Android, some up, some down, but your Google Contacts is a lead-pipe cinch with Android.
Anyway - those are my opinions.
Many good lucks on your decision!