I first became acquainted with bents after watching a video for an Airzound airhorn (which at the time I was considering buying) demonstrated by the youtube personality "CyclingMikey", who I believe rides a Challenge Fujin lowracer. IIRC he is also a driving instructor.

In several of his videos he swears by the improved motorist behavior when he rides his bent. Somehow he is more visible. This despite his beat being usually in the crowded and busy streets of London city. Furthermore he rides a lowracer and no flag either (I checked). He puts it down to the unique shape of the bike somehow catching the eye of motorists. Thus it could be inferred that a regular upright is in fact seen, but not registered/noticed by motorists, or simply it seems to be that regular cyclists are taken for granted.

My situation is much the same. I ride in a city environment with fast moving vehicles and frequent road junctions. I made the switch in light of this info. I am happy to say that it works. It is rare that I am buzzed by a motorist these days. Riding on city roads has become far more pleasant.