Yes we're doing the same. If I recall correctly it was $800 cheaper to fly out of Isla Grande than SJU. Also we coming back we would clear customs at Isla Grande which should be better than SJU.
We are fans of Island Birds and used them exclusively since Cape Air caused too much stress one too many times.
Double check me but the past several trips, Island Birds on the SJU return took us straight to the FBO (private av) terminal where we cleared in with a C&I agent. From there, we were taken by van to the main terminal.
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