My group is a pretty stable 4-6 people, plus a few more that come and go. Seafall and pandemic: Legacy were both a bit of a pain in that they had to have the same set of players every week. Risk: Legacy, less so, and Kingdom Death, it really doesn't matter- characters die so often, no one can get attached, heh. The idea that the set can run with a varied group of players, and even with multiple 'teams' is good, but how does that happen with the stickers and whatnot?
But, like I said, KD:M still has a lot of content to go through- we're just over halfway through our first campaign, and I think I've only used one monster from the expansion content (I was in on the original KS for everything except the pinups). I own it all, but ironically my friends like it more that I do. I mean, it's fun and entertaining, but as I've said before, I don't consider it a good game. Brookhaven actually looks like it might be 'good'. Hmm.