X_tan,
Bad news. Saturday, I was attending a national motocross race near Dallas. I thought that race would be a great test for the 28-300. Unfortunately, I dropped my 1DMK4 with the 28-300 attached onto a concrete driveway. I nearly vomited. The viewfinder broke and is hanging from the body. The lens mount of the 28-300 was damaged and must be replaced. I do not know if any internal damage has been done to either the body or the lens. Currently, the lens and body are packed for shipping to Canon on Tuesday. Not a good day for me.