Thanks all for the input!
This is good to know. I figure I'll go with the 5's and see how that goes. If I'm not happy with it, I can mix the 5's and 6's and see if that works for me. If so, then I'll go for the 5.5 gm ones.
I probably won't be able to get to it until next weekend at the earliest, but I'll let you know how it goes.