FYI -- I decided not to get the Big Agnes 3 person after reading about it because of the spatial footprint. The foot in your face middle person isn't our cup of tea. More like an emergency shelter, and way to heavy for that. (We got bivys, thermal sheets, etc. for that sort of business.)
The tent reviews on this site made me think -- I either want a 3 person tarp tent or a 2P double wall that could serve as a 3 person (our Tri-Lite can't do that), like the Sierra Designs Hyperlight,for a few overnights with 3 people each year -- when we have to.
Otherwise the weight is the big issue and the tarp tents, Rainshadow at 35 oz., seem to win hands down on that issue of a functional 3 season shelter as far as I can see.