I grew up on the North Shore of Vancouver, B.C. In vancouver, there has been a trend toward giant bike shops. You know, ones that are the size of a supermarket and have at least several hundred bikes in stock in a big showroom, sometimes divided into different rooms or areas for different types of bikes.
There used to be smaller shops, but they seem to have mostly disappeared, and i sorta know why. In the big stores, you can go in and they usually have what you want. Pick your model, and they'll have all the sizes, etc. In a smaller shop, if you're lucky, they'll have the model that suits you, but they'll probably only have one size. They _might_ be able to get another size if you're lucky. While some of the small stores had a lot of character, i nearly always ended up spending my money at the big stores, since they usually had what i wanted.
Anyway, i recently moved to New York, and discovered that all the stores here are TINY! Stores that were described to me as 'big' were smaller than the smallest vancouver bike store. The biggest store i've been to in Manhattan, Toga Bikes, probably had less than 65 bikes in the store, and maybe 15 real mountain bikes. Other stores have had as few as 25 bikes..
I guess part of my problem with small stores here is that (in my experience) they will usually tell you that whatever they have is perfect for you, even with frame sizes. I noticed this when i looked at the same model at two stores. One only had a large, and one only had a medium, and at both places, they unhesitatingly told me that the size they carried was absolutely perfect for me.. yeah right.
So, what size of store do you use? A tiny one? A medium sized store? A huge one with everything?
Me, i'll take a huge one any day (as long as they have decent service obviously).. but that doesn't seem to be an option in this corner of the continent..