Tim,
I think you need to prioritize those features that are important to you. We do that and find it is a blend of chassis and conversion features that influence our purchase.
Do some research on chassis features because in the 2007 to 2009 range there were some very significant changes including the ones Gary and Kevin mentioned. But don't ignore the house. I often suggest that people not consider a coach strictly based on decor, but there are important things we all want. If you will be using the coach a lot those interior features could be important. You already have a motorhome so you are not new to this.
Personally I would stay very far away from the emissions features that require the exhaust through the roof and I would avoid a coach with the Volvo engine. Detroit dealers know their engines and our buses. I think the jury is still out regarding service issues on the Volvo engine.