Other than the chassis being stretched to accommodate the extra bed then the interior (including front beds, cupboards, oven, WC and shower) is pretty much the same as our 5 year old (2 berth) Quasar derivative, which we are very pleased with. We like the addition of the fold-up kitchen bench extension which we don't have in our current van, but did have the feature in our previous Avondale. Unfortunately it can't be retro fitted as the side of the bench is curved and not straight to take the hinges.
I guess the major (hidden) advantage would be the new side panel construction as ours is the traditional method.