Thanks for all the answers!

The reason I am looking into GS and just not sticking with my regular setup are 3 reasons:
1) Avenger's shield procs - I'm missing those procs on my slaves. If GS can cast them sooner it would be nice.
2) When I'm mashing, and don't have time to look at the cooldown of my spells, I'm often casting hammer rather than something else which is off cooldown. If GS can cast them sooner it would be nice.
3) If I never had to look at my spells for cooldowns I could have more focus for other things.

So if GS could perform close to as good as my normal rotation, it might outweigh the pros for keeping all the abilities manual. Having manual control have the advantage of me being able to place my consecration more wisely (which does not matter so much with my current talent). Also I can specifically choose to use one of the ranged abilities when I know I am out of range.

emitchel and Xeneres, thanks for the example GS scripts. As emi mentioned I am also a "spam button masher" because I see no other way from keeping all the characters going effectively at different GcD cycles. So Xeneres, how often do you press your GS button when using your script?