The 64-bit VST2 version works for me in Renoise 3.1 and Tracktion 7. Not Reason 10, unfortunately, but no big deal. I never had a K3, so I'm not sure how it compares, but it seems to be a very nice plugin.
So many shitty things that get a 5 star review here, makes me wonder if it is someone connected to the development of the instrument/plug that passes out stars like candy. If this is 5 star what is then Synth 1, the free version of Dune/Zampler or OBXD???? Just to mention a few of the many, many free synths out there.