.if I fork out some $ and buy an Ambassador membership, would I likely get the Ambassador benefits on a "free stay", and would I get a one room level upgrade? If so, would the latter room be reasonably sized? Thanks in advance
Yes, you should likely get that treatment. If you don't like the room you get, you can always go back to the front desk and ask for a better room. Unless you have the bad luck of staying while a large conference has booked up all the good rooms, you should be fine.