I have that issue, and I will re-read it again tonight. (It was about the BMC Trailfox, btw.)
I just did a quick internet search on "ht vs. fs", and EVERY SINGLE article that I could find would list the positive and negative attributes of each, and they ALL said that FS had a weight and efficiency detriment, compared to HT. I do agree that propedal platforms are getting becoming more efficient though, so that gap has to be closing.