I have the corbin I recently bought and hope things will be better on my upcoming trip. I did buy an Airhawk R today though after reading that most people say they help quite a bit. Figure it won't hurt to have if the corbin does'nt fit the bill on my ride
Now don't get me wrong, I like my Corbin, but I'd suggest you take it for a long day ride before committing to riding with just it for multiple days. I will often start out with the Sheepskin on the Corbin and then later in the day, when it starts to hurt, I'll slip a Thermarest camp cushion under the sheepskin with just a smidgen of air. Not quite an Airhawk, but it helps.