I have a kahler in my roadstar, and I must say it feels a lot nicer to play on than a floyd (palm muting etc), individual string adjustment is also useful as the roadstar fretboard isn't 100 percent flat. I think the real strength of the kahler is that you can pull up the trem a lot more, especially if you have super low action, as with a floyd, as you pull up, the strings pull toward the fretboard. But, with a kahler, you can't drop the strings until they're all floppy, ie, floyd does better dive bombs.
Also, as someone said, if you have a nice wood guitar you don't have to ruin it to install a kahler, and even though my trem is really really old (early 80's?) it still feels indestructible.
However, the trem arm design of kahlers (I have an old US made kahler pro) is kind of retarded, it screws in like a fender bridge, and unfortunately with mine I can't find a stiff point so I can flick it up and down. The Ibanez edge pro trem arm, IMO, is much better.