I've got a LBO with a three piece vestibule which works really well for two guys with a stove in the center. The BCS2 would offer more room, and if you want a lot of room get a 6 or 8 man.
Gear of all kinds are alike in that it is cheaper to buy what you want NOW, instead of going through several cheaper alternatives and loosing a bit of money on the sale of each before buying what you wanted in the first place.
