I did the same about a year ago. Large enough that the community is extremely diverse with a wide range of life experiences but small enough that you'll start to recognize certain people. Also the completely linear threads means people will actually see what you post and not just ignore any conversation that isn't part of the top 10 most uploaded replies.

Yeah, and the simple $10 one-time-fee actually is surprisingly effective at filtering out spam bots and people who post crap content. People don't just make an account in thirty seconds and create a bunch of spam until they're banned, or at least they don't do that much because it would get relatively expensive fairly quickly.