I wouldn't call MetaFilter a particularly high quality community. Discussions there can have just as many trite and trollish comments as your average subreddit.

How MetaFilter differs is in that it features a rigid, hierarchical moderation structure, with gatekeepers who ensure posted content meets the stringent politically-correct tastes of its leadership. As a result I have seen legitimately interesting, good-faith discussion censored there, for no other reason than that it offended the sensibilities of some moderator. (This article was removed by a moderator, for example: http://www.linuxjournal.com/content/girls-and-software)

It is a huge mistake to confuse enforced, intellectually sterile homogeneity for quality.