Therm-a-Rest 2009 Prolite

I have the old version. The Prolite 4 to be precise. The new 2009 model is 1.5 inches thick. The 2008 one that I have is 2.5 inches thick. The 2009 one weights 8ozs less though. Is the sacrific in thickness worth it? If you have other recommendations, that is fine as well. However, I do not want your typical air matress with no cushion and all air. Those things give me neck cramps.