I play with a Xbox controller on a PC. I don't have any grips with the GCD. As a healer it force me to take precaution, to heal a bit more in advance to take account of it. In fights it didn't badder me yet, as long as the enemies have the same delay, which I still see at level 22. It's not a major strategy elements, but it still valid. On a graphical standpoint, it gives time to the CPU/internet to process commands, and reduce on the screen the FX effects crap that would ensue...if everyone would do commands simultaneously. Visibility in fights is also important, the GDC is about that too, in my opinion.