FYI, I just ordered 3-7 in the CB an 8-PW in the MB.
I don't know exactly when I will switch to these as my plan is to use the same shafts I have in my irons now...
I need to do it when I don't have a tournament coming up as I need to play with these first to see how the distances change (and ensure I like the heads). We have tournaments once a month and I typically play most of them.