The installation was painless. Note that you should probably unstick the option to launch GSAK at the end of the installation as crossover doesn't consider the installation complete until GSAK exits otherwise.
I did get some errors the first few times I started GSAK after the installation. I couldn't read the error however as the dialog window was severely undersized. I just pressed ENTER which popped up a request to submit an error report then options to do various fixes and restart. Once I got past that it seems to work fine.
One thing that didn't work is setup of your particular GPS (presumably because it tries to talk to the device at a lower level than supported emulation). I chose Garmin and Generic USB and it worked okay for my Nuvi 1390.