I have never used the other version (KW/HT-65) but have been told by members here, vendors etc that it is of lesser quality. I don't know if it is a different formulation or what. I like the King Deluxe stones just fine for what they are. The 1200 has amazing, to me, feedback but it is not the fastest stone. The 6k is good but nothing special. The 800 is a good stone for a dark Kasumi finish but a little rough. The 1k exists... I think the KDS is a good budget option but not any better of a choice than the Cerax. I've not used the Imanish combo so I can't compare. King stones are value stones, not more and not less. Again, that is just my opinion.
However, the 1k and 2k hyper stones are on my list. Also, I've not tried the King 8k and I hear it is a great stone as well. People seem to like the 300 too.