looks like I miss out on all my plat upgrades b/c everyone posting to this thread beat me to it! Personally, I haven't had a lot of luck with upgrades as a plat... a handful of times out of 50 or so stays this year.
However, I do love *wood hotels, and all those 500-point plat bonuses do add up. And I've never had a problem finding availability to burn those pts on awards. ^
Of course, toward the end of the year, I started staying in a Hilton (sorry!) b/c it was more convenient and significanly nicer than a nearby Sheraton, which was the other option. Even though Hilton had no interest in matching my status (or even offering a challenge), the big bathroom and comfy bed won me over.
So basically, I'd consider your comfort/ convenience first. But also consider 500 bonus pts * your anticipated # of stays. Good luck with your decision!