I have one. 6.0L w/@135k. Nothing major. Good trucks. Too bad they stopped making 2500 Suburbans.
One thing to check: The dreaded "pump rub."
The transfer case gets a pinhole in the right rear corner from a bad design.
Some rub through, others last a long time before they rub through.
Also, listen for fuel pump whine, and if present, along with a twitchy gas gauge, then you will need a fuel pump soon.
Lastly, check that the HVAC blend door works. These are problematic on 2000-2006 GM trucks/SUVs.
The stick open/closed.
I fixed mine after scouring the internet for fixes... that didn't work.
This looks like a base model, so it looks to have the simpler HVAC controls.
Hope this helps.