definetly get them, some accidents are so bad frame sliders aren't going to protect the plastic perfectly, but its better than nothing, and especially if you have some stupid little driveway tip over it will land on the slider, if you loop the bike at 120 a steel cage couldn't be gaurunteed to save it... when i was trailering mine to NC the other week one of the tie downs came lose and the bike tipped over and landed on the side wall of the bed, i was like fuck and walked over but it just happened to land right on the slider and didn't do anything at all

alot of bikes offer two kinds, one where you have to use a circular saw to cut a hole in the fairing for the slider, and another kind that has a bracket which moves the slider to a opening in the body work so no modification is required, DO NOT get the bracketed kind, i've read countless stories and seen it too many times in person where the bracket just snaps off, if you take your time and make the hole perfect you can't even tell you cut the fairing