Like Jon,I really like OTR air and heat.I know that it cost more from Prevost as well as more labor and materials for the converter and also weighs more.A Liberty without OTR is IMHO almost a sin in 2009,it will be interesting to see if an old Liberty customer buys this one or someone that has never had bus air.I don't know but I bet that it has 2 Outback 3500 watt inverters with six 8D batteries and 4 cruise airs.Traveling in the desert when two cruise airs overheat just turn on the other two until the others cool down and then begin the cycle again.