I will only add one other note of caution, as I would opt for the Meadow Club as well.....
Don't be lulled into thinking that the Meadow Club is an easy hop, skip and jump from whereever else you might be in Northern California. If you schedule this one, try not to cut any of your timing too close, and make it the only course of the day, if necessary, as it is pretty darn remote (for Marin County) and not too easy to navigate to, and that's not even allowing for the notorious traffic...
That having been said, of those two, I would definitely make the effort to get to the Meadow Club, as it is first-rate...
I found the greens/green complexes at Green Hills to be very challenging, although it's been a few years now so I can't speak for more recent findings. If it's an either/or and the Meadow club doesn't pan out, you shouldn't pass on Green Hills because of it, but the Mackenzie nuances are better in evidence now at Meadow...