Why do the later 900's feel like slouches compared to the early ones?

I'm no stranger to buying a car and flying out and driving it back but those were "specialty" cars that are owned by enthusiasts so I know the type of care they got. Most people buy trucks and ride the hell out of them and then toss them. I've looked at so many of these trucks that had horrible paint work when I was told the paint was in great shape, or they say little/no rust and then get there and the rust is so bad the chrome is peeling off the wheels, or the interiors are ragged (seat bolster flat, buttons wearing off, etc), or the whole truck just creaks and moans when driven because it baked in the sun all day every day with no care. That's why the rust scares me because all of them that I've looked at so far are so eat up that I wouldn't want them at any price. I don't want to worry about rusty brake lines, if bolts will break trying to change the engine mounts, etc.

They sent me a lot of pictures and most of the rust that looks bad is under the hood. I can see at least one broken manifold bolt that will need to be fixed and I'm sure more will break trying to get it apart so might as well rip it all off and put headers on it ($$). It doesn't look like the bolts for the heat shields will come off either and if the y-pipe studs break, that's hours of drilling those out so I'd expect to replace the manifolds at the very least if I touch them. It also looks a little wet on the back of the oil pan in one picture but not on the front in another so the rear main seal might be starting to leak so that would need doing eventually. KBB says the truck is worth $18k in good condition so I offered $17k and they said they couldn't do that. The rust is my main issue but I don't want to immediately dump a ton of money into it, at least if I'm paying "full price."

Definitely odd! My 07 Denali with over 100k was much faster then my 10 Escalade with 66k miles. I then added an intake and BB tune and still my Denali was faster! Sad....

[QUOTE="91RS, post: 1255690, member: 2775"
I found a 2009 Escalade about 2.5 hours away I was wanting to go look at but it spent 3 years and 26k miles in Michigan so I'm scared of the rust. QUOTE]

I purchase a 13 Avalanche in Michigan, which was sold in Ohio (Lima Auto Mall) and everything is solid underneath. I spent a day and a half under the rear end, Fluid Film the inside of the frame rails and Rust Restorer from the axel back. When I pickup up the car fax on the AV I found it was actually originally delivered to the dealer I deal with in Blissfield when new. They must have done a dealer trade with Lima Auto Mall who first sold it.
Anyways there is really no way of knowing what it may look like under there... You have to eyeball it in person.

[QUOTE="91RS, post: 1255690, member: 2775"
I found a 2009 Escalade about 2.5 hours away I was wanting to go look at but it spent 3 years and 26k miles in Michigan so I'm scared of the rust. QUOTE]

I purchase a 13 Avalanche in Michigan, which was sold in Ohio (Lima Auto Mall) and everything is solid underneath. I spent a day and a half under the rear end, Fluid Film the inside of the frame rails and Rust Restorer from the axel back. When I pickup up the car fax on the AV I found it was actually originally delivered to the dealer I deal with in Blissfield when new. They must have done a dealer trade with Lima Auto Mall who first sold it.
Anyways there is really no way of knowing what it may look like under there... You have to eyeball it in person.

Sorry for the multiple post, my computer is having problems confirming posting to this site.