I have the #1, and it's perfect for 2 people. But you can also serve a crowd of 6-8... or more... no problem. My #1 can fit up to:
3-4 racks of ribs (depending on how many shelves you have). Each rack cut in half, and one rack per shelf.
Two 3-4 pound chickens
One huge pork butt
One 14 pound turkey
15+ pound brisket, cut in half and placed on two racks.
I bought the #1 because of how space efficient it is to store (and it suits my meat output needs 99.9% of the time). It disappears behind a chair on my back porch when not in use. I've had mine for over two years, and I still would not want a larger one. But the general consensus here is that if you are considering the #2, then maybe that's what you should get. I never even considered the #2.