Bill and Kalen:
The 13th at Barnbougle is a bigger version of the 8th at Ballyneal. I'd be there's a bit more elevation change in total at BD, but due to the size of the green its a bit more stretched out. Throw in the 4th at Lost Dunes, and you have three greens with a tremendous set of contours and elevation changes.
I would say that the 4th green at Lost Dunes is the most severe I've built; in fact, there may be other greens at Lost Dunes more severe than the 8th at Ballyneal or the 13th at Barnbougle, not in elevation change but as far as being able to two-putt them.
The green at Ballyneal is only severe if you are trying to putt up to or down from the upper right hole location, which they will use one or two days per week. I almost didn't include that as part of the green, but the little bowl was up there already, so we tried to incorporate it. Right or wrong, I reasoned that if you landed on that part of the green by mistake, it was a poor shot and an almost-impossible two-putt was a fair result.
The green at Barnbougle is mostly natural [with some internal re-arranging] and is just a miracle of Nature. Again, there are places where a two-putt is very severe -- if the pin is front right, especially, you just have to keep short and left -- but there are many more spots where you can use a bowled area to get the putt much closer than an opponent who just tries to putt directly to the hole.
The 4th at Lost Dunes is created, from a flat site at the base of a steep hill on the right. It was modeled after the 8th green at High Pointe [designed by a crazy young architect, now NLE], which was based on the memory of a green at Rosapenna (Old). The hole at Lost Dunes is almost a full shot harder with the flag on the top tier, but like the 8th at Ballyneal, it's a par five which is so short that I've reached it in two, and if you screw up the third shot to put yourself in a bad place then a bogey is not such an unfair outcome. It's the guys who reach it in two and wind up making 5 or 6 who complain ... they just won't admit that their second shot really was not that that great, though it put them in position to four-putt!
But, P.S. to Sven: Be careful about comparing Barnbougle directly with Royal Melbourne! No matter what you say, one of my clients is going to be upset!