The number of interactions (over email) that I need to have with them to get even a simple request like a restaurant reservation done from Amex Platinum concierge has made me look around for alternatives. FWIW, even Facebook's assistant 'M' is far better at handling tasks that Platinum concierge.

not sure what the amex platinum version is like, but I wasn't that impressed with the visa infinite version.

I asked them to go through the craigslist of another city and find a certain car for sale, then return a list sorted by mileage and price. They couldn't do that for whatever reason and just offered to give me the KBB value.

Took me 5+ minutes to navigate their phone menu, enter my card number and get to the service.

FWIW I've been very impressed by what the Amex Plat concierge can do