Gregg4.....We have never been to WDW during a busy season, so I can't comment on just how bad it is when it's crowded. I can tell you, however, that touring is VERY enjoyable during the slower seasons. We either go in April/May...or Sept/Oct.
What kind of budget are you looking at? We are also in our 40's, if we were going without children, I'm sure we would be at one of the deluxe resorts. Perhaps Polynesian or Contemporary, or lots of folks like the Epcot area resorts, Yacht Club, Beach Club. There are very nice moderately priced resorts too, Coronado Springs Resort being our favorite. Since you aren't traveling with kids, I'd recommend staying away from the Value resorts, (All Stars), I know I'll get some flak about that, but that's just the way it is, they are themed towards kids and you'll find A LOT of them there.