Hi again everyone,thanks for your comments.
Kelvin, the GMC has a 36-gallon fuel tank. I'm not sure how that compares to the Ford F250 fuel tank, it really wasn't an issue with us. Although having a 36-gallon fuel tank will be nice.
As for how the price compares to the Ford, I think it's comparable. It really depends on the options. With the Denali, it's basically loaded. We went through the Costco auto program, and then we negotiated a price even lower than that. There was a $2,000 rebate from the manufacturer and to sweeten the deal even more, we got a $600 cash card from Costco and a $400 visa card from the dealer.
Gary, we are thinking of getting the RockTamers. It's on our wish list. The truck does have splash guards as you can see on the picture, but not sure how that compares to the mudflaps though. We do agree with you about the payload! That was our biggest reason for going with a bigger truck. Nice to know we can load up the truck bed without worrying about payload capacity!
The truck rides nice! Very quiet and comfortable. Personally, I really like the interior of the GMC over the Ford, just personal preference. We really had no complaints with the Ford F150, we were very happy with it. It just didn't have the payload capacity we felt we needed.
We're enjoying the extras we got on the GMC - for example, we didn't have built-in navigation on the Ford. Also, it's nice that every door has a door handle to grab onto when climbing into the truck. The Ford didn't have one on the driver's side - you had to grab on the wheel.
And also, the exhaust brake was a feature my husband wanted. We test drove a 2014 Ford 250, but it didn't have exhaust brakes. However, I do believe the new Ford trucks now have exhaust brakes, but I can't say for sure.
One complaint - our navigation system doesn't work! Yes, it's covered under warranty of course. But we're still waiting for the part they need to fix it, and it's been 2 weeks. According to the dealer, they are not sure how long it will take!