Can't give any recent feedback, but I had the Platinum ICC card serviced out of the UK for a few years and found the concierge service in general quite OK, especially for restaurant reservations.
On one occasion I used them for securing a restaurant booking at one high end sushi restaurant in Tokyo and, despite it took them a couple of weeks to confirm, they managed to get it. I understood they had to liaise with their Japanese counterparts so that gave me a sense that they went "the extra mile" as opposed to the easy way.
However, I think that this really depends on who you speak to -- like everything in life. Some may care more, others not so much.