That's exactly the comparison I wanted to make as well. I thought of the original Magic service as "a Visa Black Card concierge-service automated and scaled enough to target the middle class"; this just returns it to the parent concept.
Presumably the people using Magic for that sort of thing were the upper-class "money left on the table" that's being picked up here. Most Magic requests, from what I take it, are more for the same lazy-person-making-100K things like to-your-door grocery delivery that other services provide.
I've used Visa Signature concierge a couple of times and have found it to be very 'meh'. The last time I called them they seemed to have limited the scope of what they'd do to making reservations and travel arrangements.
Visa Signature concierge is very meh in comparison to the amex platinum from my experience. (I've not used a centurion concierge, though reportedly it's the same service - I find it hard to believe that they're treated with the same service level considering the requirements and fees to be eligible for a centurion card, however)
The Amex concierge team has been able to find me items at local stores when I needed things ASAP that I was having trouble finding, and also managed to snag me a limited release item that was only available at the companies' location. (That was expensive, but still less than I saw them for being resold for online. I imagine a courier service could have been used if I was familiar with any in the area, since it was basically a 'drive there, pick up, drive to UPS store, ship' type request)
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.