For what i have the 6 speed is fine. Gas millage is about the same, a little better then my 2012 1500 sierra. Better towing , the same for driving. I regularly drive fast, without the trailer. So , 75 to 80. I find myself at 90 way too often with the 2500. It just seems im going slow. Inside is about the same. Not many changes. The new , for me anyway, backup camera is kick ass for hook up the TT. The sceen and interface are good also. The flip up front seat qas the aame as when i had my 2002 siearra, lol. Power for me is way more then i had with the 1500. I never had a 2500 to compare it to. My TT is also light. Its way better then my 1500 that struggled up steep inclines. Overall it was a big upgrade. Waiting for something you want and need is like buying a TV if you keep waiting for the better model, you will always have an old one.