I've only had one experience with SWF.com, and my opinion will be deleted if I go any farther. A fluke? I hope so.
But I must say....I love my LFS. I work at one, but I love the others in town, as well. We all have different suppliers, so we work together to get things for people. The other LFS's in the area work REALLY hard to help me, a rare clownfish collecter. If you have quality LFS's, I would encourage you to support them, or they could be gone.
I see the point in some people needing an online source, however. Some people have crappy (I'm being nice with that adjective) LFS's, so they need that. But there is nothing like watching a fish eat and being able to hand pick your specimans from a good LFS.