With all due respect to Jeremy and Borneman, I love making coral i.d. guesses... and I also think I'm worth my salt.
It's fun!, and its part of what keeps me interested in this hobby even when no conclusion - even reasonable - can be reached. I think we all know nothing is absolute... its just a game, and gives people a general idea of the 'type' of growth habit in a particular SPS we're talking about.
Having pretty sizeable colonies of what I believe to be M. palawensis and M. danae in my tank, I really don't think that coral is either. I have never seen a full colony of M. undata... but I've seen a lot of frags labeled 'undata,' and they all look different! When you look at Verons shots of M. undata... it makes sense that frags of that coral could look like many different corals, based on conditions. To me, it also doesn't look like M. confusa, M. verrucosa, nor the similar species...
That said, I'd go with M. undata in the process of eliminating (at least in my opinion) the other corals mentioned.
Nice coral Darren!
b
p.s.
M. flabellata is only found in Hawaii... and I don't think that's where Jeremy's shipment came from. The verrucae (sp?) are also much larger on your frag than flabellata... again, just my opinion.