Based on this, I'd urge you to consider the #2 ... the reason is that you can't add size and you will be occasionally cooking for small groups of around four. You'd have no problem cooking your primary protein (brisket, ribs, etc.) in the #1 for a group of four but adding other things (sides, extra meats for leftovers, etc.) or space-sucking applications (beer can chicken, turkeys, etc.) might present an issue. I subscribe to the Tim "The Toolman" Taylor motto: "More Power, Arr Arr Arrrr!".
With ribs you've got the option of cutting in half and using the built-in racks or
specialty rib racks available through a variety of retailers. You also have the option of
rib hooks which will give you a more traditional means of cooking ribs.
With brisket, packer cuts don't quite fit in the #1 without some serious trimming; a #2 should give you more flexibility.
I can't speak to turkey (though a 14-16 pound bird seems about right) but on spatchcocked chickens you'll be eating up your primary real estate on each rack but you could probably squeeze three into the #2. Beer can chickens (the one has a
two-chicken design) probably will limit you to two in either unit while I can fit two double mounts easily into the #3.
In both the #1 and #2 you could probably cram more product into the smoker but you'd be dramatically reducing necessary air flow and final smoke penetration. Hope this helps, Jim ... no matter which one you choose you'll be making a solid choice.
