After my near 6-month disfunctional relationship with the Givi engine guards... I have removed them; probably for good. They looked good, they gave protection higher up on the fairing, I had mitigated vibration issues pretty well regarding the spacer (rubber tape, nylon washer, crossed tie-wrap), and had filled them with Great StuffTM to deaden what vibration was left.
Then I changed my tires to Metzler Tourances and the vibrations returned, albeit at a slightly lower RPM. I was close to a 8K service so I let it go for a few weeks. Nope after new plugs and a TBS it was still there. Odd why the tire change affected it (since it is an RPM specfic prob), but with a tuning fork phenomina - who can determine all the factors?
Givi has since my installation acknowledged "a" problem so I decided to cut the weight and take them off. (ignore the folks who say you are mechanically inept).
If they work for you they are great. If they don't, best of luck. I'm satisfied with the protection my frame sliders will provide, and in reality there are really relatively few instances when any one one protection system will work 100%. In a hard hit no one is expecting them to hold up. In a soft tip-over (where you "assist" dropping the bike) they might not even touch ground. The turn signals, brake or clutch lever, shifter, or rear brake will certainly touch ground.