Have to agree with you, David.
While the Exp-II is by far the most comfortable Rolex of the lot, it's lack of popularity is probably 'cause of the FIXED bezel. Most guys would prefer to fork out the few extra $$$ and get the GMT-II so they can have a bezel to fiddle with!!
And, of course, the WHITE dial is more popular than the BLACK; but then that again is due to the fact that there aren't too many WHITE dial sports Rollies around.
JJ