Thanks all. First time on Ryanair for many a year, and it was fine apart from the overhead locker space issue. We were a few minutes late each way so were spared the "on time" message
I would recommend Porto for a short break. In addition to the Port cellars (which are actually in Gaia, not Porto - mistaking one for the other is a bit like identifying someone as being from Manchester when they are from Salford) there's enough to see and do for a few days, and plenty of places to eat and drink. Take your walking legs though, as it is very hilly.