it really looks like a super Gilet.
It is a super gilet, a very well thought out design and robust construction. It's made by L2S and I have one, though obviously without the PBP branding.
In all seriousness, you may want to bring your floppy fit one too. The L2S gilet is quite a heavy weight material and some MAY find it too warm, depending on how balmy the nights are or, conversely, if it rains and you need a waterproof too. I didn't wear mine on both my 400 and 600, opting for my doctored-fit ex motorcycle one instead simply because it was lighter and airier.
Not suggesting you cart both around with you on PBP but give yourself the option of deciding between the two once you've seen it.