Which Would You Buy?

I am thinking about getting either GSX Ground Service or FS2Crew for my Aerosoft Airbus. I have FSCaptain and VoxATC and they add so much to the flight sim experience. I am like a flight junkie in need of my next fix However, I can only get one or the other at the moment, so my question to those that may have one or both of these is: which one could you not live without? Thanks!