I've had mixed luck with GM trucks at work... probably more due to the mechanics up at the warehouse in Helena being too lazy to properly maintain the truck fleet...
2009: '02 Chevy 2500 w/ 95k+ mi- barely has any oil in it when I picked it up (the little oil that was in it was pitch black dirty), along with a loose wiper blade. Later on in the season, I had the battery die on me twice- once out in the field (luckily my supervisor lived only a few miles away, so her husband comes to help me out)
2010: intially am given an early-to-mid '90's Chevy 1500 with 214k+ mi on it- everything works ok in the parking lot, so I proceed to drive it back towards Bozeman, only to have the rear passenger-side wheel lock up (faulty wheel bearings) on me while driving 70mph down the highway about halfway between Helena & Bozeman- supervisor's husband come with his state truck to rescue me again... talking to the warehouse mechanics in Helena, they were like "well, we took it for a test drive around the parking lot, & it did ok, & you know, wheel-bearings aren't something you can just check during routine maintenance, so there's no real way we could've seen if there was a problem with the bearings or not"
as a replacement, I am given the same '02 Chevy as the previous year (now with 105k+ mi on it)- battery problem seemingly fixed (the warehouse mechancis supposedly didn't do anything, so the problem apparently just fixed itself), only things to really go wrong are a broken wiper blade that starts flopping around when my partner tried to turn on the wipers to wipe off some morning dew, & a check engine light that came on (wasn't anything serious, though)
later on it the year, I am given a '96 GMC 1500 with 100k+ mi on it- large rusted-out holes on both muffler & tailpipe (was told by the Helena warehouse mechanics that "it may be a bit loud when you drive it (duh), but as long as the truck still drives ok, there's no need to fix it" (several months later, I was finally able to convice our vehicle accountant to let me get it fixed after saying I was starting to smell exhaust in the cab whenever I idled), later on the interior driver's door handle broke off when my partner tried to open the door, had to roll window down to grab outdside door handle for about a week before I got authorization to get it fixed. Other than that, no real mechanical problems, though.
2011 (so far this year): was given a '92 Chevy 1500 with only 69k+ mi on it, feared the worst at first when I got an e-mail from our vehicle accountant saying she believes that that truck hasn't been to Helena for service- ever. Had a couple good cracks in the windshield, tires were kinda worn out, & the horn didn't work. Took it to Helena, & had the warehouse mechanics take a good look at it- they asked if I noticed any particular problems with it on the way up- I mentioned the windshield & was told "oh yeah, that's definitely something we want to fix. Especially if the cracks are on the driver's side". When I pick it up, I see that they put nice new tires on it, but the windshield was still cracked (go figure...) & the horn still doesn't work... alterted our vehicle accountant about the horn, asking her what she wanted me to do, & never got an e-mail back (she is noctorious for not answering her phone or returning phone or e-mail messages). Despite the windshield & horn, it seems to be working ok for now, & happens to be the only state truck I've had that doesn't have some sort of rip or tear in the seat. Would still like to get a 3/4 ton... the 100 gallon water tank puts alotta strain on the 1/2 ton climbing up passes & hills... (also, just an interesting side note, I recently did some research & learned that my little Ford Ranger has a bigger payload capacity than this full size 1/2 ton!)
Hope you don't have any of those problems with your new Chevy- I think they make some decent vehicles (although Chevy/GMC will NEVER be as good as Ford!
) You'll love having a bedliner... I have one on my Ranger & love it- no dinging or denting up the bed floor when I'm tossing chunks of firewood around!