My guild does two week-end retreats each year, spring and fall. I enjoy them immensely. I usually get one quilt finished per week-end. But I learn from other quilters, get to cheer for their finishes and find new friends! Any time you get to know another person in a little deeper way it is worth it to me. Yes, I found those who say crap, shoot and $#@^! but then I also find those that laugh at errors, yell HELP! when they need it and who offer to lead a hand when sandwiching a quilt.
We go to a church camp retreat center and have 40 - 50. I know that in my area, southern Michigan, there are several homes that have been converted into week-end retreat sites. Many of my scrap booking friends go to these and they have perhaps a maximum of 8 - 10 per week-end group.