And more photos of something you've all seen before...

[Delphinus]

Oh - I thought maybe Borneman had told you or something like that.

That third one looks a little like it. The only thing is (and especially apparent on the other two links) is that it looks like it stays thin and branchy, whereas this one typically hasn't done that, the new growth is thin and branchy but the lower parts end up being one solid piece of coral. Almost similar to a table growth pattern (although it's not a table by any stretch). It actually makes for fragging pieces of older colonies a bit difficult because whereas the new branches are thin and brittle, older branches are stocky and darn near impossible to cut through with side cutters.

Interesting... I think I had seen pictures of A. valida before now that you mention it, and thought that this is a possible ID ... but in the end, anything I decide it to be is just a guess... so "purple acro" works for me.