I had a bent break lever when i dropped my bike despite having guards (with an aluminium bar). The guards were spun upwards until the lever was exposed. The Yamaha guards connect to where the mirrors are from the look of them so are much less likly to have this happen.

End result was a new break lever and having to bash the guards back into shape (the metal bar bent as well)

I'm considering changing my handgards now, but I'm also looking to get a throttle lock fitted, and with heated grips as well getting a combination that will all work together will be tricky.