One complaint I had with the BBHS diagonal is the coatings. On mine they were not that robust. I tried to clean a spot off and it was a coating flaw and by cleaning it I totally made it worse (ruined the diagonal mirror). A lot of this was my fault and lesson learned but still stings a bit, all because I didn't initially recognize that the coating failed
Sorry to hear that but I'm sure a lot of us would've done the same thing. I've been intrigued by the BBHS but at that price point the QC should be better IMHO.