Cure the sibilance problem at the mouth, not at the mic! Simply be aware of your S's and F's, and cut them short. Turn your head to the side (off axis) when you hit them, especially at the end of words. Don't look for the electronic fix to microphone technique. Learning to sing into a condenser is hard work, requires practice, and awereness of every sound you make. Mostly, the only reason I use a pop filter anymore is to partially protect the capsule from the high water content in my breath.
That's my point, that a good condenser will force you to sing better, or have the fact that you suck recorded for all time! Bottom line, if you don't like sibilants, stop hissing, and don't blame it on the mic. A mic doesn't just turn your vocal sound into an electronic signal, like a distant overhead, it's a tool you have to learn how to use. If you put your finger on the wrong fret, would you get a different guitar to fix the problem?-Richie