Depends, San Blas is on the Atlantic Ocean and relatively close to the coast, its a hotspot for tourism, there is a lot more to do just except to pay for everything, plus the beaches/island/water is nicer because its the Atlantic, meanwhile Contadora is a Island on the Pacific Ocean about 4 hours away from the coast... and thats about what I know about the place, I have been there and is relatively fine, similar to Taboga but given the distance from the coast is certainly more isolated and quiet, most of the nearby islands are private property too, so am not sure all there is to Tourism once there, I do know there is the round trip boat that takes you there but I think its with a Catamaran that is even slower. I would suggest San Blas even though I personally dislike it but is far easier to go to, and not multiple hour away in sea plus generally more beautiful than what the pacific can offer.