Be interesting to see how that thing works. I used to have a band that went around my helmet which another rider told me was brilliant as it was above car roof height and moved about a lot. He'd spotted me ahead from miles back. Eventually it snapped and now that I wear a flip front I never replaced it. I had a belt something similar to that but I was never convinced it made any difference. Living in a city centre and doing a lot of filtering one thing I notice is a difference between when I'm wearing a hi-viz Frank Thomas vest or just my usual black leathers. My habit is to watch for drivers' eye contact in the rear view mirror and then watch their front wheel. Some drivers have an instinct which is aggressive and they will automatically go to block a bike passing them. I see this happen when after making eye contact their immediate reaction is to turn the steering wheel outwards - you spot the front wheel twitch outwards even if the car isn't moving. When I am wearing hi-viz the wheel twitches out and then they re-think and it goes back again. It's not a case they they don't see me wearing leathers, it is more a case of when they go to block they then think - I'm going to look a knob knocking off a biker in hi-vis saying I didn't see him. So I reckon a hi-viz vest is worth it. I am not convinced it makes you that much easier to see, more that it curbs the aggressive streak in some motorists by making it less easy for them to ignore you.