Just an interesting figure- the last direct acceptence in Delaray Beach is Morrison, ranked 99, & the last direct acceptence in Scottsdale is Mamiit, ranked 101.
Thanks for checking that out. It's interesting, but I would still say that Scotsdale has a much more elite field. They have 3 top ten players, and the lowest seeded player is Malisse. The gap between the top 2 seeds in Scotsdale is ONE ranking place, as opposed to about 20 in Delray Beach.
The field below the top several might be equal in theory, but even the lower ranked dangerous floaters seem to have been drawn to Scotsdale... Mark P, Dent, Bjorkman, Enqvist, Ferreira... not to suggest that Delray Beach doesn't have any decent players, but really... it's no contest.
Of course geographically it makes far more sense to play Scotsdale, as it's been pointed out. The players who have just played Mexico, are more likely to want to just head north a bit then fly across the continent. Furthermore, I would assume that Scotsdale, being in the desert and all, has conditions closest to Indian Wells.
So I suppose that answers my question.