I purchased the Suburban almost a year ago and have not had a single problem out of the vehicle. The guy I purchased it from worked for a GM dealership and was the original owner of the truck. He had the engine and transmission and transfer case replaced at 45000 miles under factory warranty due to anoverheating problem. The engine and drive train now only have 55000 miles on them and perform perfectly. I use the vehicle to take my family around and also to pull my ski boat. The only flaw on the vehicle is the fuel mileage but you do not purchase a vehicle like this to get gas mileage.
It is roomy and drives great on the highway and in town driving.
I am not sure what they could improve on except maybe fuel mileage. Which is almost impossible considering the size of this truck.