Cheers. I've seen that study from Fairwheel Bikes and it makes interesting reading. I'm currently bemoaning the lack of 10 degree stems, and wondering if my back could live with a -17 degree stem on this bike. It's another 16mm drop, and I fear the answer may be no...
Gorgeous bike built up, you've done a cracking job all-in.
Carbon stems can be stiffer, or lighter, but rarely at the same time. There's marginal difference for material selection in stems, all about the way its applied. Source:
http://blog.fairwheelbikes.com/reviews-and-testing/stem-review/