I've got a cheap (10 dollar) 17t I use for hilly trips, and other than being noisier and a little rougher than my more expensive cog it hasn't really given me any issues. After about 1,500 miles on each cog neither is wearing any more than the other, and they both stay in place fine. I have front and back brakes for stopping though, so I don't know how they would perform if you're a skidder.