My 2013 520 rides just beautifully, and the linear-pull brakes that come stock on it offer plenty of stopping power, even under load, when they're adjusted properly (which should go without saying). One advantage of the new 520 over a pre-owned bike would be that a new one would come with Trek Care, i.e. a lifetime frame warranty for the original owner, plus Trek's loyalty program which offers discounts for replacement/repair parts in the event that such are needed. The rack which comes on the new 520 is pretty nice, too. It's lightweight, but very sturdy. In any case, I hope you enjoy whichever bike you decide on!