I think they're both gorgeous games weighed down by some pretty significant flaws, but I enjoyed them regardless. I'd have to go with Kuon for its unique setting. Heian-era Japan doesn't get enough attention. If you're looking for something similar to Clock Tower 3, I wouldn't say either of them really match. Both are a lot more combat-heavy than CT3. Haunting Ground was much more similar, IMO, and it's another rare PS2 horror game worth about half as much as Kuon or Rule of Rose. Kuon can get really repetitive while Rule of Rose has some frustratingly broken combat sections. It all comes down to your tolerance for flawed game design, I guess.