A let down
Booked the Sheraton Tribeca on their website. Subsequently found a better deal through Kayak, which normally should be honored by Starwood's best rate guarantee.
Starwood didn't want to honor the lower rate, as the hotel had meanwhile also adapted their rate to the lower price. And the fine print is: the rates have to be available at the same time -- not the time the customer is checking, but the time SPG is checking. This makes a lot of sense, if rates at competitor websites disappear, but it's a clear breach of trust, if it's actually the Starwood hotel that adapts the rate to the lower one. SPG recoginzed that and made two (interesting) recommendations: 
1) Never make an actual reservation, before a BRG claim is approved... well, does that make business sense for them? I'll let you decide.
2) Contact the hotel directly, as they are (still) offering the lower rate even to walk in customers. They should typically match it. Well they didn't: The assitant FO manager was insulting me, because I was making "illicit" claims and the General manager, even confronted with the threat that I would take my following 3 nights elsewhere wasn't smart enough to see, what kind of havoc he caused, by insisting on his lousy 40$ (which he wasn't getting from any other walk-in customer, but insisted on collecting from a loyal SPG Platinum...) Congratulations, 3 nights of revenue lost, definitely will never come back to this hotel, and now that I requalified for Plat (in July), will bring up my stays with Hilton & Intercontinental.... Hopefully the guy is not paid by any kind of economic results of his franchise or SPG.
Let's be clear: BRG is just an annoying marketing feature, they shouldn't be offering it, rather honor Platinum privileges, no matter the channel.
Oh yeah: the hotel. Modern lobby, location next to subway station, the rooms (was Platinum upgraded to what they called a Junior Suite: a 4th floor room with a sofa, next to the lifts and a view through dirty curtains onto a inner courtyard wall about 10 feet away... really not worth it. The Platinum lounge has a cool terrace (closed evenings though), the staff seems to have been snatched away from the local fastfood outlet or a drycleaner without any training... In the 45 minute I was there (8:30am) they subsequently ran out of plates, cream cheese, orange juice, preserves and then the lady broke the espresso machine while trying to put some beans in there.... no way to replace either of that in a decent breakfast time frame.
A once in a lifetime experience... exactly once, and please: DON'T GO there, it's not worth it.