I have only seen this issue when taking it out of drive and not only on steep hills. It is a real concern though. I would hate to be on black bear, switch to reverse, hit the gas, and roll forward...what about the problem with the 12s and 13 s getting the transmission stuck in neutral after coming up the hill in 4lo or the bad heads in the 12s there are some still out there. you can probably get a 07-11 with some mods even done already.
I personally If I didn't have the kids and had to do it over. I would buy a TJ (kept mine) and beat the shit out of it and wait til 2016 to see if they actually put in a diesel.