I've been running the N-Gear Jump Stop for the last year on my 1x9 and it's worked great for what it is meant for. I've never dropped a chain on the inside but without a bash guard or chain guide its popped off the outside a number of times even using a single speed chainring. My cheapo solution was to modify the N-Stop, rode it today over some pretty rocky terrain and it worked perfect. Will give an update as I get more miles on it.
Cheapest, lightest chain guide?-photo1_zps66121e86.jpg
Cheapest, lightest chain guide?-photo2_zps19acf107.jpg