Why are lo pros good to ride round london?

Do many people still use Low Pros on the track? I've never seen one used there.

I found one in a shop at the weekend, proper classic Raleigh Team Banana, campy pista cranks, disk wheels, was very tempted but there was no chance it would fit me. Does anyone know how much something like that would go for?

Not much but I do remember a photo of one at an Aussie race recently.
I'm sure I posted it here but can't be bothered searching. Maybe national masters or something?