To start I am not big on American cars, but I have a family of 9 and so I need something to haul people. No Japanese or German truck was going to cut it. I have owned a previous 97 suburban and had little problems (ex. door handle broke and water pump needed replacement).
I am going to give a very honest opinion of this truck. I will start with the exterior. For one it's a little bland and has few details. I like how the truck looks small on the outside (meanwhile its huge on the inside) compared to Ford trucks (Ford trucks are tall, bulky and too wide). I am extremely disappointed to find that this truck has no rear or front sensors (meanwhile a small BMW 3 series has it as an option). As well, I would have loved a power trunk. Other than that the exterior is okay. Nothing to gawk at.
As for the interior... its not too bad. The leather quality is good considering this is an American truck and I must admit the seats are incredibly comfortable. Every single person who has driven with me has made a great comment about the seats. You almost want to sleep in them. The dash is a little too boring for me, but extremely functional. There is plenty of leg space even in the back bench. The Bose sound system is fantastic producing crisp sound. The DVD player is great (a must have for long trips). The interior is overall good and I can't complain too much about it.
Now for performance. For a truck, this thing has great handling. Of course there is body roll, but it isn't bad considering its 6000 pounds. The ride quality is incredibly smooth and can handle any bumps the road can throw. Under heavy acceleration, the engine roars and the truck can pull off a half decent 0-60 time (for a truck of course). The engine is very smooth most of the time. In bad conditions... I wouldn't want to be driving anything else. I live in Canada and our winters can be brutal. I strongly recommend the optional Stabilitrak. It really keeps the car going straight and where you want it to. In snow, the truck stays on its course and doesn't want to slip (which is good). I feel very safe driving this thing (maybe too safe).
I realize this truck doesn't appeal to everyone. It has a very small market. But if you are looking for something of this size and caliber than you can't go wrong. Hope this helps.