I've been to a handful of large shows (AQS, MQS and KCRQF--all a couple of times) I love going to see all the awesome quilts and get great ideas. and I like seeing a lot of vendors in one spot that carry such a variety of items that may not be available close by. I do agree that the crowds and costs can be significant "bad" factors, but like others, I save up my $$ to go and treat it like my college basketball loving DH does major tournaments---as a special treat to enjoy an interest I really enjoy. My guild also has an annual "small" show--admission is low, there are about 150 quilts hung, we aren't able to get more than 2-3 vendors, etc.
The big difference I see is that the big shows are for those of us that quilt and want to check out new--new quilt ideas, notions, classes. The smaller shows are more for quilters and non-quilting public--a chance to see lovely quilts that may be more in the comfort zone of non-quilts, etc.
But I wonder how many of you are like me and got totally hooked on the creative process of quilting-regardless of the type of quilting you like--by going to one of those bigger shows and seeing such variety? I can actually name the show where I stood there gazing at these amazing quilts and told myself--quilting is something I want to do!