I've stayed at the Hilton and the Doubletree. Of the two, I believe the Hilton is more upscale and in general a bit nicer, but the Doubletree was perfectly acceptable, so if cost is a factor, I'd pocket the $400 savings of the Doubletree.
Hilton also has Character Breakfast on Sundays. I was going to stay here when we go in November, but decided to bite the bullet and stay on property instead.
The Hilton is very nice. What dates are you staying? The reason I ask is that they usually have some very good rates. We were there last Xmas and I got a rate of $79/night.