Hey sure they do.
I go to my regular equipment supplier Peninsula Shopping Centre. The boss there or the staff there are always more than happy to let me test out the lenses on my camera body. In fact, I do find myself testing and learning more about each lens, how sharp, how good the colour and the contrast, before I make decision on which one I would buy. I test various brands but don't know, mostly end up still buying Canon lenses.
When it comes to buying lenses, I believe shouldn't be too hasty. Really read and review your desired one and ask to have it tested out. I think most importantly still is the way you approach the staff. Be sincere and warm, and any self-respecting sales person will respond positively. Of course, being knowledgeable makes all the difference because they will know that you have readup on your stuff.
.. of course if for some unknown reason, the moment you step in, and the sales guys give you black face or something like that, then trust your vibes and quickly step out lah. They probably don't need your business. Lolx...