Experience with Concierge
The service was from "VIP Desk Service". I needed a reservation for a Saturday night at one the Gorden Ramsey's Restaurants in Tokyo for next week. Called in on a Sunday afternoon. A few hours later they had a reservation secured (They had quoted up to 48 hours for a response.) ^
They also offered to look into entertainment before or after dinner if I wanted. I took them up on the offer and will see what they come up with.
All in all, they were very fast and saved me the time, money and hassle of trying to cold call Tokyo.