has anyone used gettransfers in barcelona ...are they good or not
Get a taxi and forget transfers. Easier and cheaper
From your previous question I understand that you're going to Estartit, so a taxi or a transfer can be expensive, depending on the number of passengers.
There are, of course, public transport options.
From the other question I see that Lynda gave you a few options so I can add a bit to that.
You can take the train to Girona (you can take the train from T2 and change at Passeig de Gracia, for the fast train you'll need to change at Sants). and From Girona the E2 bus to Estartit (from the bus station, which is near the train station)
You can also take the Sarfa bus from the airport, unfortunately the bus to Estartit is only during the summer (from July) so you can take one to the nearby town Torroella de Montgrí (there are 2 buses, at 12:10 1nd 19:40) and from there the local AMPSA bus to Estartit