I had an opportunity to purchase my 4dr LT in 2010 with only 65k miles on it. Today it has 85k on it and it's still going strong. The normal things are wearing out that I would expect to on a 15 year old truck, but I have not had to put in any major repairs thus far. The previous owner was a meticulous maintainer of the vehicle and I am continuing the trend. Comfort wise you can not beat it. Recently drove 11 hours to the Big Bend area of TX. Did mostly offroad rock and dirt roads while there and she was a beast. Towing is good, but upgraded shocks are recommended to distribute weight better. As for brute strength, I would take this tahoe over a new one any day!
Comfort, strength, reliability and overall looks. It looks more like a truck than a soccer mom large SUV. I like the smooth lines and how everything is tied in on the exterior. Todays Tahoe's are built more like cars with plastic all over it. The 98 is metal! There are readily available parts available for this age of Tahoe. It doesn't take many aftermarket upgrades to distinguish your Tahoe from the other tens of thousands Tahoe's on the road today.
Third row seat option. Having one would be nice when your hauling a few extra kids around. Not a big fan of the barn doors in the back. Tailgating just ain't the same. Have to agree with what most others said about the drivers seat leather wearing out. Headlight and Taillight plastic getting hazy. But then again so are everyone else's and their cars are newer!