The floors will not be rusty.
I worked on these things for quite a while at independent shops and the dealer and never saw one with any unusual rust issues (at least 03/04s). What I did see all the time though were failed rear air suspensions, leaking headgaskets, leaking front cover gaskets, leaking oil pan gaskets, leaking intake gaskets. Bad MAF sensors. Vacuum leaks. Bad door latches leading to alarm problems. Failed front driveshafts leading to replacement of transmission assembly and transfer case assembly. Leaking transmission output seals. Leaking rear axle hub o-rings. Worn hubs leading to bad ABS sensor readings. "Shuttle valve" failure in ABS modulator.
I did see a lot of the bad blocks as well. That was very common.
Thats everything off the top of my head.
AND don't be surprised when it needs front and rear pads and rotors every 20k and tires every 25k.