I'm looking at the therm a rest prolite plus and the NeoAir Sleeping Pads. At the present time we are car to the camp site family so weight is not a big issue. Other than price what are the differences?

If weight is no issue, you can find a much cheaper mattress out there that will suffice in both warmth and comfort. The Neo Air is meant to serve backpacking enthusiasts with the lightest most comfortable pad Thermarest can off. The differences you will find are thickness and insulative quality. While the Prolite has more foam for insulation, it is also much thinner and therefore less comfortable. The Neo is a true air matress with a thin layer of insulation laminated to the interior wall for added warmth. Check the warmth rating and go try them out in a store. I'll bet you will find the Neo to be the most comfortable matress out there.