Iv'e used it in the past. It's not a feature I use too often, but it's nice to have when you're in an unfamiliar area and you're looking for a place to get dinner (on a holiday) and they tell you what's around, the type of cuisine, and the price range. I mean, you could google it yourself and call, but I like recommendations
Now if you're trying to get a last minute reservation at an upscale restaurant on a Friday night, I would call a concierge with more connections like Amex Plat/Centurion, Palladium, etc. For a non-annual fee card like the TY Preferred, I have no complaints though.
[font=Palatino Linotype][/font]Wallet: Citi Thank You Preferred, Marriott Premier
Sock Drawer: Debit Card
(Future: JPMorgan Palladium)