In my own limited experience with FC, I have been very impressed, Richard sums it up well. Having the signal generator in the system allows the PC to deal more with interpolation and "looking ahead" rather than timing issues. I run everything at 115K baud serially and have never had a problem with timing or communication.
I do wish FC had a better macro capability, but that may be my own limited knowledge. Specifically, I'd like to set up my system so that when I do a tool swap, it'll do an XY traverse to a fixture (Z touch probe), descend, make contact, reset program Z=0, and resume the g-code file, without manual intervention.
The FC pendant looks nice but is priced very high. I am going to try one of these, recommended by a zone member -
http://www.ymouse.com/
I think a pendant will make jogging and zeroing much simpler than the mouse.
Swede