I had the Biondi, used it for 1 season and replaced it with the GIVI. The Biondi was a bit too short and exhibited distorted optics when viewing through the curved top portion (that drove me crazy and was too scary for city driving).
I have plenty of experience sizing and cutting my windshields. I cut mine down considerably so I never saw the weakness noted in the Just Gotta Scoot review (where his cracked). In fact, the cut/shorter GIVI now has a stronger and better engineered mount than the Biondi.