Started with a Coleman Roadtrip and it lasted like 3 years. Did it's job ok but was a PITA to clean, cooked extremely uneven and hot in areas due to the burners being so close to the grate and I was not crazy about the coating on the grates which wound up chipping and rusting. What happened to the Roadtrip after 3years you ask? See DE88ROX's post above. Lit it once and noticed the burner was not where the flame was coming from. The flame was coming from under the burner nd shutting off the valve did not put it out. Doing an autopsy revealed this to be nothing more than Coleman stove burners. Bought the smaller Weber Q with flip out shelves and thermometer, for close to the same price as the Roadtrip I might add, and have been 100% satisfied. Cooks as well as the Weber Silver C I have on my deck at home and love. My Dad and FIL also rave about theirs after years of throwing out cheap grills.
2 inch leveling kit on my 2005 Titan from PRG and lifter the rear with a 1.5" block from PRG. Not a bit of difference towing or in MPG. Titans don't come with a chin spoiler, so doubtful 2" makes any difference there as there is already drag. Just be aware if you "level" a truck by lifting the front end you usually make it look like it is bumper dragging when you tow or load it up. The raked appearance is actually preload for when you start to load the truck up.
3 sets of Carlisles on 3 different TT's. Never had an issue. Duro's that came on the 3rd TT had severe sidewall cracking in less than a year. On the advice of my trusted local tire shop, I got radial Carlisles installed and they have been great. Owner of the shop says he sells tons of them for trailers. Everything from boats to landscaper to utility to camper trailers and rarely sees them come back for replacement before they are worn out.