JMHwrote a review of SRAM Guide RSC Disc Brake on October 30, 2014
Familiarity: I've used it several times
After the dark years of elixir, it looked like Shimano was the only game in town. The XO Trail brakes made huge improvements and IMO were competitive with XT and XTR, but the Guide brake solves the final few annoyances with the Trail and is undoubtedly my new favorite brake. If you are familiar with the Trail, just imagine the best they ever felt after a perfect bleed and fresh pads, and that's how these have felt from day one. No more inconsistent rear lever feel once the pads wear in a bit. Remains to be seen if the pads need to be replaced after 50% use like XTR or XO Trail, but I feel it's a small price to pay to keep your brakes feeling flawless.