Spending roughly $150 to secure gold is most likely worth it. You'll start enjoying upgrades and other benefits when you travel. How valuable those are depend on where you stay (limited service vs. full service, US vs. overseas).

Spending the extra $350 to get platinum is probably not worth it unless you expect to staying at platinum frequency next year. Plats only get a few extra benefits relative to Golds. Upgrades should theoretically come more frequently, but my personal experience is that properties that are good at giving upgrades give them to Golds as well as Plats.

For the people who are at 71 ~ 72 nights already and are thinking of a $350 mattress run to hit plat my answer is a bit different. First of all, you're more frequent travelers. Things like the higher point bonus are going to add up faster for you. Second, if you can book a trip that's not purely a mattress run the effective cost is a lot less than $350. I would not throw away $350 to gain status via phony meetings or rooms I don't even care to occupy. But if I had the opportunity to manufacture a couple of enjoyable little weekend getaways with my wife, coincidentally at MR properties that helped me cinch status, I would absolutely spend $350 on that. I've done that sort of thing before, and we've both enjoyed it.