I'm a rabbit newbie but I've read a lot, and since those with more experience haven't had time to chime in yet, I'll throw some thoughts out there.
I'm tempted to switch to a colony setting at some point.
Colonies are awesome. I love watching my buns interact and hop around together. I get swarmed at feeding time, and it's neat to walk in amongst the buns, trying not to step on anyone. I don't think I'd enjoy my buns nearly so much raising in cages.
Weighing the pros How much space would, say...one buck and two to three does require? Bearing in mind that for each litter, I'd move all kits to a "grow-out" pen once weaned, so I don't think I really need to worry about space for all the bebbies.
There just is no real answer to this question. A basic rule of thumb seems to be 30 square feet per doe. More is nice. If you're removing the kits to grow out, you might be able to get away with less. Especially if you add some levels to add more area (although that makes cleaning harder).
So many factors effect how much space you need: how your does get along, how often you breed, how big your average litters are...
Oh, and another thing...I'm willing to bet I'd have to dress out all my current meat does and either use a pair of sisters from a litter here or buy a pair of young sister does, right?
Again, depends on your does. If they're generally mellow girls, they may get along. Some does are fighters, some will get along with anyone. This is where more space is nice. It betters your odds of does getting along.
As much as I love my colony, it does present its problems. Mine is 15' x 6'. I have 1 adult doe. I bought 2 does originally, one died on me (I'm growing out a replacement in the colony now). I bred them at the same time, and when they kindled I only had one nest with 11 kits. I never could tell if they shared a nest, or if all the kits belonged to one doe or the other. One of the flaws of a colony.
I had originally hoped to leave the buck in the colony full time and just let the buns be buns. So far I haven't had much luck with that. I removed him the first time the does were due to kindle since they were first time moms. The second time I tried to leave him, but he ended up harassing the doe endlessly the day before she kindled so I removed him again. Then I didn't remove my growing does quick enough, and horny buck actually started attacking the young girls. I'm hoping he will mellow with age, and if you're removing kits you won't have that particular problem anyway. If I recall correctly, Akane has been able to leave her buck in the colony full time, but she has a lot more space than I do. I know Maggie splits her space, has one doe on each side, and alternates the buck between the two areas.
The beautiful thing about a colony is that it's easy to change and work with. There just is no single setup that works for everyone all the time. Nothing about my colony has gone according to plan, but I've learned and adapted and enjoyed doing it.