That is a very sexy build. I still think it screams a set of Fibre-Lyte custom full aero rings but short of that (you now me), I think this is a dead sexy build. I would love to get a pair of those S-Works cranks for my SLC build and then get custom aero rings for them.
Thank you sir, and the chainrings are temporary. I am probably going to go with Sram TT rings, just because they are relatively inexpensive, and I haven't heard anything bad about them. These FSA ones aren't the best when it comes to shifting, and they are heavy. I would really like full aero Fibre-Lytes, and I might go that route. I just don't want to spend that much money on chainrings.
I have bike building ADD lately. I've been working on this, and my Allez, getting them where I want them. My S2 had a few changes over the winter as well. I need to update the S2 thread soon, and start one on the Allez. I rode the Allez 50miles yesterday, and I was thoroughly impressed by it. I couldn't believe an aluminum bike would ride that well. It wasn't harsh at all, but still felt faster, snappier, and more responsive than my Trek 5200 it replaced.
As for the S works cranks for your SLC. I am told that you can run the mountain version with Lightning/Rotor 3D+/Vuma Quad BB cups. The road version is made to only work with BB30/OSBB width frames. I like the Specialized cranks design a little better than the Lightnings on my S2. Since they are made for a narrower BB shell, there is a bit more ankle clearance on the crank arms. Other than that they are very similar, and the Specialized units are much cheaper. I have not weighed them, believe it or not, but I hear they are a little heavier than the Lightnings.