I have owned my Silverado for about 6 months now, and I have had not one problem with the design quality. The engine performance is superb and towing isnt a problem. My 4wd reg cab SB can tow a impressivly 8,100lbs with the v8 5300. I normally tow about 4500lbs with the factory hitch at 80mph effortlessly. Towing like this, there are no major shakes or rattles, bumps are smooth and the truck handles great. I have driven a non Z71 and it was a bit smoother on pavement compared to the stardard base. But offroad performance is much better.
Automatic 4x4 - on the fly 4x4 - automatic locking read differential - Seating is very comfortable on long mile trips (1000+)
Interior - plastic trim, and dash. Dont get me wrong, the interior is NICE, but the cheaper plastic dash and trim panels could use some improvement. It's a TRUCK so it should'nt be equipped with a cheap-o carpet headlight. I think a vinyl headliner is one thing GM should change.