I like my Shangri La 3 a lot, it's becoming my go-to shelter. Providing all-season shelter for 2 men with equipmient at only 23oz offers an excellent amount of square footage per ounce, with plenty of comfortable sitting room. Though i've only pitched it in the yard overnight a few times and taken a couple afternoon lunch-naps on beach hikes/picnics and havent gotten it out into the back country yet really.
My intent is to use it with a pair of solo net-tents, at 7-9oz a piece(can't decide between Zpacks, SMD, Bearpaw). Instead fo one big 1lb net/tub, Each hiker carries his own inner net and is responsible for keeping his own space clean or making his own mess. No mixing up gear. In fair weather the SL3 can be pitched with only 1 trekking pole to save time and convenience of having to lash two together.
As far as hex, mid, tipi? Just get one. You'll love it! For two, perhaps the square "mid" footprint might be the most efficient, but once you get into larger ones, the perimeter shape becomes less important and you'll have plenty of useful internal space.