I love them on the right guitar, if they are set up properly. 99% of all Floyd problems occur because people don't know how to set them up properly, or they use cheap imported versions made of shoddy materials. I wouldn't want one on all my guitars, and I wouldn't think of putting one on a guitar like a Les Paul. But having at least one Floyd guitar opens up a whole new dimensions of sounds that you can't get from a hardtail, or from a vintage trem without tuning issues. The tuning stability of a properly set up Floyd is amazing, although I prefer mine set for downward use only to maximize sustain and eliminate any tuning problems.
The licensed versions just don't cut it, you need to go with an original Floyd or a Schaller Floyd for best results. There are a few exceptions, such as the Peavey Wolfgang trems and some of the high-end Ibanez trems, but for the most part, stick with the original or the Schaller.
Ryan