I have had both and the new body style and perfer the 01-02 over the 03-06. But make sure it has Hydro boost braking that's the only real issues with the 01 & 02 year models that and the radio is a Din & a half , the mirrors don't power fold and no steering wheel controls.
You can get the dash bezel to make it a double din for real cheap or trim yours. The power fold mirrors can be added, I am seeing about swapping to the newer Steering wheel and using the new wire harness.
The buttons and swiths in the 03 and up the wear out and IMO that's when GM started to have so issues with Finances.
Now depending on what you want it for the Yukons can come with a 6.0L which is a night and day difference power and performance wise.