Help on WWM width?
I went with the 56" width and I'm very happy. There is tons of room in it, and for the few grams extra its worth it. I was using a GT Nano before which is 48" so I wanted more than 4" extra, and 8" did the trick. The GT was just too small (also only 9' long) to sleep in all night. My WWM is roomy and very comfortable. I think the extra length and proper sag makes a big difference too. I'm 5'10" and 160lbs btw.