Sorry I haven't gotten back in touch with you. I forgot!
You already are having this bike built, and I'm sure it isn't cheap. If you hadn't put the money down for it, I'd say reconsider and get the Bike Friday. But since you have already started on it, I say go with the S & S couplers. It's always good that you can compact your bike down for a suitcase easily for travel.
Koffee