Starwood Preferred Guest - W for Valentine's Day

I'm currently trying to pick a W for next Valentine's day - originally was thinking new orleans, but it looks like that won't happen now. Though they're in very different climates, I'm think of Montreal or Mexico city. I've read good things in this forum about both. I'll be a plat by then, so an upgrade is another consideration... Any suggestions?

I've stayed at the W Montreal a few times and have tremendously enjoyed not only the hotel (minus one forgettable incident), but the the city itself. Montreal is about as romantic a city as it gets--clean, safe, excellent architecture, great restaurants, good nightlife, etc. Just keep in mind that Feb. is a very cold month there. The only downside I can think of is that as a Plat. I've only gotten one upgrade the three times I've stayed at the W (albeit, never to a suite).

I'll be making my first trip to Mexico City over New Years and have three award nights booked at the W. I'll post a trip report when I return, but have heard generally good things about it. Anyone know how they are with upgrades for Plats?