If I'm reading you right, your only reason for considering selling is the "roof problems". I can't say I've had similiar thoughts, and maybe it's not worth 2 cents, but here are my thoughts:
Let me start with an example of this "weak" roof system that Winnie uses. My Journey sat through the worst that hurricane Charley had to offer. Gusts over 180 pretty much straight on the drivers side. Just about eveything outside like mirrors, vents, antennaes, lights, etc. were either destroyed or blown completely off. But you know what? That weak Winnebago roof stayed on and when I checked it last week, all the side seams are still tight. Yes, I went all the way down both sides pushing in on the roof and watching for any movement. There was none.
I know some people have had legitimate problems, some of them major. I wonder if some of the problems are from that particular roof not being properly attached to the supporting structure of the roof. That seam down the side is certainly not the whole thing that keeps the roof on, it's only a small part of the system, but seems to generate all the criticism.
So, my $.02 is that, if you otherwise like the unit, stick with it - you may be upgrading into worse problems. On the other hand, if you're looking for an excuse to upgrade, I'd say dump that lousy roof and get something better...
Best of luck with your decision!