Comparing identical prices new-to-new, the C & B+ will be the better built unit in the under $150,000 price range. Once you start spending over $150,000, the A's starts to show better quality. A visual indicator rule-of-thumb is that when the "A" has a front door forward of the passenger seat like a Grey Hound bus, the rest of the coach is getting better attention. Diesel pushers are another indicator. I believe the two go hand-in-hand, front door feature and diesel pusher.
Back in 2007 when shopping for a new rig at a local RV dealer tent sale, I walked through brand new class A's that were priced on the windshield at $59,000. A quick walk thru had me leaving swiftly. The interior construction was inferior which turned me off to them.
Strangely I had trouble breathing in some class A units. Adhesives and material outgassing had me nearly passing-out.
I agree with just about all comments made by everyone prior. So many good points shared regarding crash safety, servicing, entry/exit, drivability, etc. I favor the class B+ for the travel style my wife and I do. But if we were full-timing, I would consider a short-as possible "A" diesel pusher for the extra storage and how the cab area becomes a very nice part of the living room.