When you step into the world of zero turns you will find that there are more than a dozen options in each deck size and ranging from somewhat inexpensive consumer models to all out commercial models.
I am partial to the Toro models; I owned an SS4225 when it still had the Kohler 22hp engine. I also had mine equipped with the Recycler Kit, Anti-vibration Mat and Armrest Kit. I lived on a small 1/4 acre lot and the mower did a very nice job of leaving a nice cut with little to no visible clippings with the mulch kit installed. The Kohler engine was quite powerful but loud. Outside of the Toro I have only owned an Exmark ZTR which has a Briggs engine. My only experience with a Kawasaki was an FR730V 24hp on a Husqvarna rider and that engine was actually quieter than the Kohler and of course had more power and torque. The FR600 should be very similar to the 730 that is had and will be fuel efficient, quiet and smooth running. The Raptor has a nicely built deck but are prone to clogging. This may be the only "issue" considering what you are paying for. Mowing only in ideal conditions would hopefully address this issue. Otherwise, if you like the mower and it is in your budget, I say you should go for it.