This is my third Denali pick up. Huge buyers remorse buying black but that's my fault. It does look amazing few hrs after its washed. Was really wanting the 6.0 and eight speed tranny but they're so hard to come by I had to settle for the 5.3 and the six speed. My 07 had alot more power it seems. Plus it was all wheel drive. But I am getting around 16 miles per gallon instead of 13.5 with my old Denali. Still working through the countless menus on the electronics. I'm over my trial for the Wi-Fi and was not impressed.The drivetrain has a vibration at around 41 miles an hour that I need to take back to the dealer and have checked out. It was an insane amount of money but I'm not unhappy.
UPDATED from 10/2015 I have owned this truck for 24 months- mileage now at 34,452. GPS roof antenna unit shorted out within a week after purchase or was likely not working when I purchased the truck. I believe it had a defective seal on the roof. Replaced by dealer. Nice looking truck. Decent fuel mileage. The truck says I am averaging over lifetime18.6mpg, it has about 23,452k miles so far. My truck has the 5.3L w/6 speed transmission/ 3.42 rear axle ratio. I opted for this engine configuration thinking it may get better mileage than the 6.2L/8 speed trans. The truck handles much like a Corvette on sharp turns at higher speeds. Not crazy about the ride; however its ride is MUCH better when carrying a heavy object in the bed or towing my utility trailer with a heavy zero turn mower loaded. I have the 4x4 Denali model which has the magnetic shocks. I drove another new GMC truck with the V-6 engine while my Denali truck was getting the GPS antenna roof unit replaced which took over a week to obtain the parts needed. I really liked the lower priced V-6 truck, although the interior creature comforts was NO comparison to my completely creature comfort-loaded Denali model, which was the reason I bought it (and the front grill). Both trucks are quiet riding. Horrible price tag. No complaints so far after 15 months (2 recalls and the info center needed updating).
Went to the dealer thinking new Suburban I ended up with a Sierra Denali! Briefly stated, I have had Suburbans for 20+ years to haul materials for my business and personal use i.e. hauling black labs, gear for various outdoor adventures, etc. I actually have actually used a Suburban for what the vehicle was initially intended! Unfortunately, the new recently redesigned Suburban is an engineering disaster for folks like me. The rear storage area is much smaller and chopped up. Also, if you have to crawl in the back you darn near need a ladder to get in. It's clear that GM has targeting soccer moms for the new Suburban. It's strictly a people hauler...period. So, I just happened to look at a Sierra Denali crew cab pickup. After a test drive, I was ready to buy. The back seat area is roomier than a Suburban and will seat 5 comfortably. I could go on and on, but the bottom line is I love this vehicle. Best of all, it cost far less than a comparably equipped Suburban!
I use my '15 GMC SLT 4X4 for highway trips to Rochester, Minnesota, in the winter more than anything else. It drives and rides very good. Power is pretty good, and gas mileage is better than average for a full sized half ton truck. The high hood limits close up visibility for parking. The most important thing is....my wife likes it (if Mama's happy, everybody's happy). My only complaints are...1) - the shifting of the transmission is a little mushy, and 2) - the high beams are not bright enough.
Reading all of the reviews made me want to post one. Specifically in response to someone who obviously had a really negative experience with this truck and wanted the warn the consumer. Well I want to do the opposite. I drive a crew cab SLT with the 5.8L V8 4WD as a daily commuter in VT. We get the hot weather and the coldest of the cold. I log a min of 50 miles a day. I'm incredibly pragmatic and evaluated every truck, cost/quality/ride etc... I ended slightly blowing my budget for this selection. It's not a Denali but essentially in name only (and maybe magnetic suspension). Otherwise I have every bell and whistle, 20 Inch luxury rims, folding mirrors, hot/cold seats, premium leather, wide running boards and more. To put it simply this is the best vehicle I've ever owned and don't know that I could ask for more. Now I will admit I'm relatively young, 32, so perhaps the advanced controls come really easy to me, but I find everything to be intuitive. My favorite feature is the ability to call up Siri in 2 seconds and direct her to do my bidding. I've asked for songs to be played that I don't own but it's found on apple radio in 3 seconds. The feature I did shut off almost immediately was the lane departure assist. Either I cross the lines all of the time or the roads here are narrow but my rear end was vibrating worse than a stripper riding the sibian on the Howard Stern channel. Aside from absurd comfort, phenomenal amenities and an awesome look the gas mileage for an engine of this size is nuts. I'm getting an avg. of 20 MPG, my old V6 BMW barely got that but now I can tow a boat if I feel the need. Addressing some common issues I will say that I've noticed the weird shifting at certain speeds. It is disconcerting but it happens very rarely to me. The other concern is the headlights, with everything on I don't have an issue but I can see how it's a bit dim. To be honest slightly shocked it's not a higher quality bulb considering the money put into the headlights on these new rigs. I'll post again if issues arise but I can say that if you can afford it and want a truck, you won't find a more luxurious option. **The folding back seat in the crew cab is game changing. Full size dog bed, tires, golf and even seat down packed with people it works great!