Good question. It depends. No matter your opinion, it's not practical at some speaker meetings with large groups and/or anniversaries etc. I also notice that wherever I've been, no matter what, a female speaker will be SRO and every woman there will wait to talk to her after the meeting. Just makes sense to me as a guy not to disrupt that.
If the speaker is a home group member or friend of mine, I'll stick around for a while and say thanks once everyone else has.