Q: I plan to visit Barcelona and I would like to know which one is more recommended: Barcelona Card or T-10 Transport Ticket?
A: Actually the two cards are completely different. The answer to your question depends on what attractions do you want to visit in Barcelona.
Though Barcelona Card provides free transport inside Barcelona, it is not worth to purchase it only to enjoy free transport. If you do not plan to visit those attractions with free access or a significant discount that are provided by Barcelona Card, it is not recommended to buy the card.
In case you are looking to save money on transportation you will do a better deal if you choose one between the regular discount cards related to the public transportation of Barcelona. You can choose between a free daily pass or three days cards, or you can buy the T10 Transport Ticket. The latter one can be obtained at all of the metro stations in Barcelona and in contrast with Barcelona Card, it is not personalized, so it can be used by more than one person.