Since this first came up, we just returned (last week) from OKW where DH played 4 times and used the voucher/free transportation every time. Right now he'd recommend Magnolia. Lake Buena Vista's greens are currently in very poor conditions (although DH got compensated for complaining) and Palm just doesn't drain as well as Magnolia if it's rainy (which it was). Otherwise Palm and Magnolia were both good courses, just the slight edge to Magnolia because of the rain.
The voucher system worked out well. DH stopped by the night before, just to let them know, but I don't think it's necessary. Otherwise, just show up in the morning, get your voucher inside at the concierge, go out to bell services who'll call you a taxi, and within about 5 minute, you're on your way. And the voucher includes the tip too.
