I tow a 28.5' Wildwood 26TBSS, empty is is about 5800 lbs and 800+ lbs of tongue weight. Loaded I would guess it is over 7500 lbs and I have measured the tongue weight loaded and it has always been between 1200-1300 lbs. This would exceed the hitch rating of any 2007+ Suburban or Tahoe. This is one reason I chose a 3/4 ton Suburban of 2006 or older where the hitches were rated up to 1500 lbs of tongue weight and are replaceable. I have seen where someone upgraded the hitch on a newer suburban but had to slightly modify the frame to make the Curt hitch fit. They also had additional steel plates welded in to make sure it was solid. I would likely go that route if I needed to replace my Suburban in the future and still wanted an SUV.
If you can keep your tongue weight within your hitch ratings and not go over your GVWR or rear axle weight rating, it would seem that the shorter rear overhang of the Tahoe would compensate for the shorter wheelbase and with a good hitch, they would perform in a similar fashion. A 3/4 ton would perform better but would not be necessary. We travel long distances and I wanted the extra stability of the 3/4 ton Suburban and do not regret it. I have also towed a smaller/lighter trailer with my Buick Wagon that was way over its ratings and axle ratings for about 8000 miles of towing over a 6 year period and was reasonably happy with how it performed as well.
How much you load up your trailer will make a big difference in if you can stay under your ratings. What do you tow with today?