We've been staying in Signature at MGM about 10 times since 2007. It used to be a good facility with wonderful service, until this time. Called in front desk, asking for 2 extra blankets for kid, it turned out they cannot help because we booked thru hotels.com and the room was managed by a different property management company. Cannot get the blankets until the next day because the service was gone for the day (like 4pm, :-)).
And if you book room managed by this company (fallon...) be aware there will be no daily cleaning as you'd expect from Signature properties.
I was told at check out that signature is now managed by 5 different companies, some of those (apparently fallon being one of them) are lacking certain basic services (daily cleaning, extra blankets). So it's better to book directly at Signature official site to make sure you get the room and service you want.