I've been living this topic for at least 3 years now. We went from around 20 to 60 in about a year and a half. First, realize that most of the people that were around for a couple years before the explosive growth are probably going to be most affected and put off by the growth while most of the new people will feel at home with more new people.
My advice is to accept that growth is inevitable and account for it ahead of time. I realize some clubs want to be as "Papazian" as possible and not worry about structure or bylaws but I promise you that it's easier to put it all in place before growth starts or gets out of hand.
When growth is due primarily to local, active, participating members (i.e. people that want to show up to meetings), I think there are two primary paths to take. 1) Select a meeting location to stick with and size the club based on the space available. 2) Grow organically and select meeting locations as necessary.
This doesn't address the pros and cons of smaller or larger clubs at all. It's just that you can't commit to a restrictive meeting location AND have no growth plan in place at the same time. Sardines don't make happy members.
When we finally realized that we had 60 members, no growth strategy, no room left and no accepted form of decision making/conflict resolution, we had a near meltdown. People who wanted to affect change were frustrated. The president at the time suggested we form a steering committee to spread out some of the work of the officers and the first goal was to draft bylaws.
I can post more about our bylaws on the other thread, but here are the highlights of our current structure:
President, Treasurer, Secretary are the three officers. Additional steering members are the most recent ex-president and two additional elected representatives. Any suggestions or grievances get made to the committee and they first have a shot at solving it with full consensus. If consensus cannot be reached, it goes to a full club vote. It's sort of democratic in a way, but some faith is put on elected officials to keep petty crap from clogging the meeting.
We don't accept beer tourists into the club. We've decided through majority vote that we like our smaller meeting location (a brew pub) and therefore must cap membership. The club is focused on homebrewing so you have to a be a homebrewer to join. Of course, we probably wouldn't be this restrictive if we had room for more people.