The 2014 Tuscany DOES have an all fiberglass roof (for those who care. I've had both and am happy with either).
In reviewing the two coaches looks like Thor has a bigger engine (450 vs 400 HP).
Thor also runs about $20K less than Winnie.
I looked at Winnie before buying my motorhome and was shocked at the poor workmanship. Drawers that hadn't even been sanded, loose or missing trim, wrinkled wallpaper. etc. etc. I had fully expected to buy Winnebago based on what I had read but did a 180 after looking at them carefully. I'm happy with my Thor, like their service (excellent) and believe they provide a lot more value for the money. IMO----YMMV.