We are a group of four arriving in Barcelona from Canada. Should we just get a taxi to our apartment or try the train. Our apartment is near the Sagrada Familia.
A taxi might be more cost and definitely more time efficient. Especially since your hotel is near Sagrada Familia, which is not near Placa Catalunya. You'd then have to take the metro to get to your apartment (it's a long walk).
You should know though that the airport bus is generally a more efficient option than the train. Runs more frequently, departs near the main terminals and takes you right to Placa Catalunya. But still, a taxi will probably be better for you.
I agree with Douglas , above....for one, the airport bus would be less expensive, but for four, the price differential will be less. Take the taxi.
Rick's Spain book estimates about €35 for an airport-to-downtown connection, plus €1 for each piece of luggage. That sounds like a good investment for four jet-lagged people. Even later, when you have your bearings and are not carrying luggage, taxis within the city can be a good value for the group, perhaps €10 to cross the central area.