I'm going w/the Big Apples. I did some test-rolls last night on rolling resistance. There's a five-block downhill coast from my house that I did three times for each of my three tire choices. Here are the results:
Bontrager XR-1: 1:41, 1:40, 1:45
Halo Twin Rail: 1:45, 1:39, 1:46
Schwalbe Big Apple: 1:35, 1:33, 1:32
My method may be flawed, and I realize there is more than just rolling resistance to consider, but I'm going to go with the Big Apples this year.
If I have a chance to get in to a bike shop today or tomorrow and buy a narrower, more suitable tire, I will. But right now, given what I have, I'm choosing the Big Apple. I know it's totally wrong, but there are actually very few "correct" bikes at this particular Triathlon. There was quite a high percentage of "run what ya brung" riders last year, including myself.
It's a 13.6 mile sprint, btw.