my partner and I were interested in doing this by train as a side trip during the week that we are in Barcelona. From my reading it seems like a nice destination. Any thoughts/recommendations on this city?
We stayed near Canet-en-Roussillon near Perpignan last year. We stayed at a Mercure hotel which was in the process of changing to an All Seasons hotel. I think that was to be the new name. We spent four days there near the end of April. Our hotel overlooked the water and we could walk to lots of little restuarants. The area had a very beachy feel. We had stopped in Collioure but couldn't find a parking place because it was so crowded. We took a day trip to Ceret to visit the "modern" art museum. We had also been to Carcassonne and stayed in Couiza. We visited a number of the Cathar castles. We climbed Peyrepertuse. I wanted to ride le Petit Train Jaune but it wasn't running due to a train strike. Since we are going back to the area this fall, I plan to ride the train then. if you want to send me a private message, perhaps I can give you some additional information.
Not too much to do in Perpigan, IMO to make it a sidetrip. Beaches nrby are tiny, stone and xtra crowded. Carcassone is a terrific medieval fortress but a long way to go just for that. The beaches around Barcelona costa del sol are very nice and I prefer.