Well, some huge (and involuntary) changes have happened since I posted this question... So I can't run benchmarks now to give you real data anymore. But I can tell you that it was a great solution at the time! We beat the heck out of it for 2 months and never had any problems. Our biggest searches ran no more than 3 seconds, with N<1000 searches running at <1 sec.
But now, I'm in a MySQL environment instead of Oracle. MySQL allows you to input multiple rows in one query as a list. Eliminating the file creation and external executable call to sqlloader can only speed things up more.
Recently, a few related posts here popped up which had some other good ideas. Super Search
is choking on me, so I can't find them right now. If you're still seeking answers, toss a fresh post at SoPW
with some specific questions so we can beat this topic around a little again. :)