I went through this same decision process three months ago, 2500 mega cab vs 3500 mega cab??? Price not really alot different, gas or diesel, unless you go with the dually axle and the Aisin Transmission, price added for those are about $4000extra. The information that helped me make my decision was what my intended use of the truck was going to be, in my case towing a fifth wheel is the final use, the 2500 has the same towing trating as the 3500, actually a couple of hundred pound higher but close enough to same they are the same, so what other difference are there? payload 2500=2200lbs in the bed 3500=4400lbs in the bed, as most fifths in the size I'm looking at weigh in around 2000lbs tongue weight, I didn't what to max out the payload right at the start. We choose the 3500 laramie CTD. It is supposed to arrive today or tomorrow, can't wait to get it. Ride wise I drove both and found the 3500 slightly harsher in ride but nothing I wasn't willing to live with. We didn't get the new air ride suspension for two reasons, 1 wasn't available yet 2- not sure if I wanted a system never used before, I like new products to have ayear or two use to work out the bugs prior to me owing them. I suggest you drive both like I did and decide for yourself. Hope this helped a little.
