Wow, first post after a long time of membership, impressive!
In my case I was given a one-level room upgrade. It was stated as such in my welcome letter. So it went from a deluxe Sakura something to a Sakura corner or something like that. It seems like with the upgrades they're trying to do expectation management by explicitly noting the one-level upgrade.
The Club breakfast was pretty substantial; they had a cook who would make omelets or such to order.
That being said, I don't know if I'd spend the $315 in your case...if it's your first time to DC, there is just so much to do and so many places to go, I'd encourage you to spend as much time out as possible.