Weaknesses: Shifting is less precise than old 3x9, brakes suck.. tiny levers, poor modulation, noisy (scream like a howler monkey to be exact), chain is crossed and sucks or falls off chainring constantly. Lots of different size and types of fasteners (allen and torx, many sizes). Gearing ratios suck, I've changed to raceface rings with 26-38 and its better but still not the same as having a 32 tooth middle ring (which I always rode in with 3x cranks).
WTF? Do people actually like this stuff? I've rode SRAM XO since they introduced trigger shifters so when I built my new bike I just defaulted to SRAM XO 2x10. As I built the bike up I was shocked that I needed both allen keys and torx in several sizes, my first thought was how much it would suck to work on this stuff in the middle of a 24 hour race, you would need a toolbox to have all the tools!
After a few rides I was gobsmacked on how crappy the gearing was, I was constantly cross chained in either chainring, I changed to a smaller 38 tooth but still I'm crossed over all the time and don't tell me the outer ring is more like a middle as sighting down the chain its pretty crossed up.
The narrow chain makes it want to climb off the chainring easily aka chain suck or drop.. They now make a chain guide so obviously I'm not the only one with this issue, guess I'll be buying one soon unless I punt this stuff and go back to 3x and probably go to XTR as I now have a bad taste from SRAM.