Danny M Hwrote a review of FSA SL-K Carbon ITC Seatpost SB20/-10 on May 27, 2017
Familiarity: I returned this product before using it
First off, this seat post is beautiful, light and seems to be built very well. I got this for a Kestrel Legend road bike so that I can use the forward offset to switch the geometry a bit for triathlons. Unfortunately, my seat tube angle is 73.0 degrees and with the -10mm offset my saddle sits just barely (5 degrees or less) above horizontal and that is enough to put pressure on my perineum. I hate to do it but am returning this seat post.
This seems like a great seatpost but if you plan on using the -10mm offset make sure your seat tube angle is greater than 73.0 and/or your saddle rails are slightly less than horizontal to compensate.