I joined our local guild after 30 years of never connecting on the right weekend! Our guild is huge (over 450 members), but feels small because of the number of small groups (10-20 members) covering every aspect of quilting you can imagine. We have assigned groups and drop in groups, days and evenings. No Quilt Police, and enough members that you can ignore the cliques that inevitably develop in a large group.
There are a bunch of reasons I like the group; older members willingly help younger members develop their craft (quilting age, not physical age - some 30 somethings help some beginning quilters in their 80s :)); we contribute in a big way to our local community and the world - recently sent $1,000 to a guild in Joplin, MO after the tornado; we have fun, both with speakers and events.
I joined when I retired with the specific intent to improve my quilting and contribute back to our community. I have to say I'm getting more out of it than I put into it.