Actually I'm very interested, as a one-off I wanted my (now very post-retirement) special trip to be first class London/Barca on the train and ferry over to the island and back.
Obvs covid finished that for me, but I'm hoping Manchester > Paris, Paris > Barca, Barca > Ibiza and then either fly home or return the same way.
Think it's also possible to do London > Barca in a day? Anyhow that's now some time off, hopefully between then and now I can find a companion to enjoy the trip with me. he or she will have to have a few bob though - but advance first's aren't all that expensive.