In Florence/Firenze we stayed at a "small luxury hotel of the world" collection hotel (via Hyatt); it was spectacular! We didn't splurge for a suite, but their "base" rooms were amazing, we had a incredible very personal greeting from the night porter at 1:30am including Prosecco and cookies (flight was delayed).

They had a 24/7 concierge service. We used them for restaurant reservations twice. However I'm not sure it was really the best, despite everything else about the hotel being top notch. The first night he recommended a "simple" restaurant which was actually the least good place we ate in our entire trip. Italian food is astounding everywhere at every price point so despite being the "worst" it was still very good, but that was underwhelming. The next one was also "simple" as the manager of the hotel assured us and it was much better; they had a large wine list and so on. It was partly our fault for not setting this up further in advance, however. I suspect that Velocity Black would have done a better job at securing last minute reservations or recommendations. We don't need Michelin stars every time but we do like out of the way, unusual hole in the wall excellent places, or hip places, and actually the Platinum concierge used to be able to do this fairly well, but no more.

In Milan we just stayed at a mid-tier hotel that probably had some sort of concierge but didn't bother trying to use them. In Paris it was just a layover at the airport and we stayed at the airport Sheraton (which I highly recommend if you have a layover at CDG), again didn't try the concierge. I would have loved to get help from something like Velocity Black however. We had a great time on our trip but a responsive concierge with a good reputation for fulfilling requests would have been nice.