Love our '07 'Hoe with the 5.3/3:73 for towing. Handles close to 4 tons of SeaRay cruiser great. Ours has the 20" wheels so no matter what you tow you have to run it in "3" because the engine runs so slow in OD. That 5.3 is buttery smooth and I've found the engine RPMs to be spot on for towing. Runs fast enough to have good power, but not too fast that it is over-revving. It actually pulls my big boat down the interstate better than my '04 GMC HD PU w/6.0 gas 4:11 rear end.
We have owned ours since new and it now has a little over 110K on it. I like the short wheelbase for towing because it is so darn maneuverable. and it was my wifes DD when we got it. She simply would not drive something as big as a Suburban. That said, fuel economy is pretty much identical between the short & long WB models, and the longer WB is more stable for towing, plus the extra room. Something to think about that before you buy.
As already stated the Tahoe & Yukon are the same vehicle. For me, I liked the looks the of Tahoe soo much better than the Yukon. Same reason I bought my GMC HD in '04. Hated the Avalanche front end on the Chevy. But if you look at both I think you'll find the GMC to be slightly more upscale on the interior.
The Bad:
AFM - Active fuel Manangement. Google it. You'll find all kinds of oil consumption issues due to the 4 cylinders shutting down. Our Tahoe started giving us issues around 70K. Currently it uses a quart every 1500 miles. Comparitively, the GMC, with a 160K doesn't burn a drop. Anyways make sure you don't end up with a vehicle that you have to add oil to between oil changes.
Autoride - If you look at one with the auto ride suspension make sure it is working. The system levels the vehicle with air shocks in the rear and also adjusts dampening of all 4 shocks using an onboard compressor. Great for towing. The system last about 5 years before the rear air shocks start to leak causing the compressor to run until it burns itself out. It's expensive to fix, even if you do it yourself. They have kits to convert to regular shocks if that tells you anything. The one in our Tahoe is completely shot. But I loved the ride when it worked which is why I will spend the money to fix it.
Rust - I've noticed many of the these 7-8 year old GMT-900 SUVs are already starting to rust in MN. I've got bubbling under the paint in many places in the doors and rear hatch where the outer skin is seamed to the inner door frame . My buddy dumped his '07 Avalanche last year due to this. My '04 has none of this. If your not in the rust belt maybe not a big deal. But GM definitely dropped the ball someplace in the corrosion dept. My '97 Tahoe had zero rust when it was 7 years old. GM went backwards in this respect IMO.
Hope this helps.