Their sharp curvilinear top lines and how they starkly and dramatically twist and turn with and against the lines of other architectural elements as well as with other natural top lines of holes and sites is pretty stunning to see.
Tom, I often search for the words to describe their unique appearance (the Australian set of MacKenziesque bunker styles). Your description is as good as I've seen...
But, I think the curvilinear lines are the result of Russell and Morcon's styling of MacKenzie's concept. I tend to think that Mac was more responsible for the routing and use of the land's contouring to strategically and adroitly place the bunkers, while their look was Russell and Morcom's.
The reason I think that is looking at Tom Doak's book on AM, the drawings always show more hairy lip and some space between greenside bunkers and putting surface (not a lot of space mind you). But, even in the old photos of AM playing at his courses in CA, one generally sees the maintenance and even placement of some of the most artistic AM bunkers as being not so much cut into the bowels of the greens as we see at the Australian courses. I think that perhaps the early influences and stylings of AM at Alwoodey and Moortown and such have the similar stylings of the CA courses of Valley, Meadow, Haggin, Pasa, etc. And, of couse ANGC. But, most all of those do have hairy lips and some space between putting surface and bunker edge.
It seems that Don Placek from Doak's team has the best skill at drawing and depicting the curvilinear twists and bends of the bunkers that AM designed.
There are a couple of bunkers at Wild Horse that are mowed into the bowels of the green, fall-in style. But they don't have the curvilinear lines that AM and Russel-Morcom's have.
I think one of the only courses that really has the same stylistic allure of the curvilinear lines that twist and bend with and against the scoops of bunker bowls and top lines is Riviera. The difference in the top lines seems to be that Riviera maintains them rolled up and under like a boom of grass that suggests a green wave, and the Aussie style is to cut them with a straight razor. Either way, Riv and Royal Melbourne are the two most compelling and alluring styles for my taste.
But, if I hear TEP correctly, I think that AM might have been more on the same line of thinking stylistically that the tops should be a bit scruffy, mixed with wisps of grasses and some bare frostings of sand. I don't think he actually envisioned the razor cuts of the edges. Not that I dislike that look. I do see some of AM's drawings with deep encroachment into the putting surface bowels (with apparent grassy buffer areas). Some of these seem to mimic the jagged edges of how the sea at CPC cut into the land mass in jagged fashion. I see those as different from his drawings of boomers.