A couple of years back, SRAM recalled 10 spd PowerLocks (one time use masterlink) due to cracks. In the event you have a 10 spd and the masterlink is breaking, that might be the answer. The suspect link had a production code of "M" or "N". See http://www.cyclingnews.com/news/sram...luntary-recall

I've had great results with SRAM for mountain (9 spd) and road (10 spd). I did not like the one-use master link on the 10 spd model, so I switched to KMC. With ~1500 miles on the KMC, I prefer it to the SRAM. Not only does it have a reuseable master link, it shift nice and has performed flawlessly.