I have the s4 system and used it on one 3d bow shoot, took the binos off and havent used it since. The top piece wasent wide enough to protect the eyecups so i left the eyecup covers on and while walking it sqeaked horribly. I have vortex viper 10x42 binos and bought the large s4 as thats what i was told i needed, while walking through rough terrain the binos would fall out of the s4 harness. The actuall straps and harness are a great idea but the place where the binos ride needs some more work. Going back to the crooked horn old school harness. BTW I am not bashing s4, i have the s4 sidewinder evo for the rangefinder and love it.