Thanks so much for your interesting and informative responses.
Gareth's point about the Cap's bow having height restrictions is interesting. Superfast VII VIII and X all use theirs, albeit over two levels, and they're essentially the same design as the Cap.
As for Plymouth, why ABP don't spend some money on the terminal, the linkspan and a covered gangway is a mystery. I was unimpressed with the whole set up when I went on the PA to Santander a few years ago as a foot passenger.
Why is there an unused linkspan so close to the main one and was it ever intended to be u