Matt MacIver:
The resemblance of the 7th green at Ballyneal to the 7th at Crystal Downs is certainly not a coincidence (although the fact they are both the 7th hole, is).
I had been looking for many years to build a green which had some of the same character as MacKenzie's boomerang at Crystal Downs. It took me that long to find a good site for one -- and I almost missed it, at that. The green site for the 7th at Ballyneal was a narrow half-pipe rather than a boomerang bowl, so it wasn't obvious at first glance that a green like this could work.
Jim Colton asked earlier how much of an influence Crystal Downs has had on my own designs. I'd say probably as much as any other course in the world, or at least right up there with St. Andrews, National Golf Links, Royal Melbourne, and a handful of others. It is the course that cemented my belief that short par-4's are the key to the best courses in the world; and certainly I have always admired its wild set of greens, although I don't think I've ever built a course with greens quite that difficult.
As for specific examples, other than the hole at Ballyneal, the first one I think of is the fifth hole at High Pointe. I tried to make the tee shot there (to the top of a ridge, or over it) similar in character to the tee shot of #15 at Crystal Downs, to where the good player would probably want to back off the tee shot a bit to avoid an awkward downhill stance for the pitch to the green. Later on, the ownership at High Pointe added a new back tee to make you hit driver to the crest, ruining that idea!
We also started a hole at The Rawls Course with the 15th at Crystal Downs in mind ... the par-4 11th. Unfortunately, I haven't played that one enough to know if there is any playing resemblance.
And I've tried three times to build a green similar to the 13th at Crystal Downs (a Maxwell concept -- he also used it for a hole or two at Old Town Club). The 7th at Black Forest was the first try, but I thought that turned out too severe; the 5th at Apache Stronghold was a little better; and the 3rd at Riverfront is better. But then I decided I was trying to use that idea too much, so I've only built one like it in the last ten years -- the 9th at St. Andrews Beach, which is one of my personal favorites that we've built.