I've been using Quicksilver as my launcher for several months now. I was using Launchbar, which I liked, but I switched, and, for one reason or another, haven't switched back. At any rate, one of the first things I do when setting up a new user account on a Mac is to install Quicksilver and make sure it launches when I log in.

As far as the criticism of the icon, I can see how it might be confused with the symbol for females. The astrological symbol for the planet Mercury just happens to be similar. The element mercury is nicknamed "quicksilver." Once you get the associations, the icon makes sense. (See how it looks like a pool of mercury?)