I would call the captivate anything but crippled. I compared my Captivate with a friends Incredible, and the Captivate is hands down a better phone.
Can you load side loaded apps? (without Phil and Jerry's little work around). As I understand it you can't and AT&T has no intention of reversing their stance on that.
It may seem great now, but how about 8-9 month from now?
You may want to do some research. HTC has a track record of actually upgrading their phones, Samsung has always been the opposite. Yes the Samsung phones will get Froyo and almost certainly Gingerbread (but probably later than the rest of us) but it is very unlikely that they will get anything beyond that.
No one disputes that the screen is amazing but Samsung has a reputation for overall poor device build quality and leaving their customers high and dry on software upgrades. Phil and Jerry on the podcast saying they think that's not gonna be the case with the Galaxy X phones does not mean that it will happen. The DInc is getting Froyo, Gingerbread, and almost certainly at least one major upgrade beyond that if the phone can physically support it.
The newest device always seems faster than the one that is a few months old but that isn't necessarily the case. I don't have one so I cant say for sure, but I am very skeptical. My DInc blows the Evo out of the water, and it is newer device. I've also heard numerous people put the DInc and the X head to head and had the X loose, so yeah ...