I can't speak for the egg style but we purchased a used Trailmanor this past summer and have been very happy. The only cabinets that would be considered flimsy would be the one around the bath room as they are the only ones that fold up. As far as holding heat or cold we camp in 100 degree temps with high humidity this past summer and the a/c on low cool kept us very comfortable. The pull great behind my Tacoma and are actually lower in height that my truck with the camper shell.
I only have an 84" garage door opening so we had to go with a folding type or pop up style. And we didn't want to deal with canvas and ran across the Trailmanors which is hard sided.
As far as setting one up it takes less than 5 minutes to pop it up and get the inside set up.