Only the GI-D balls slow down the meter, and it's definitely worth trying to play this way. Some of the advanced clubs, like Raptures and the Spider putter, already have a slow meter, so using them in conjunction with GI-D balls makes it easier than ever to hit excellent shots.
I agree getting to play Wolf Creek as a stroke-play course would be awesome. But, I'm afraid WGT already said they don't plan to add the full Wolf Creek course. We're very likely to be presented with St. Andrews in the next few months, though.
Over at TWO, they just made Wolf Creek available for stroke play. But, the game continues to be unplayable for me. (Ball can't be seen, close-up views of sand dunes are shown instead of fairways & greens.) Also, TWO's Wolf Creek really is cartoonish (at least on my PC), it just can't be compared with that magnificent glory of HD photographs of the same course available here in the CTTH challenge.