Never personally bought anything there, but it's been around for a while, has a large number of reviews on Yelp and seems legit. When I went there last week, all of the Alpina that I was looking at was 100% authentic.
There's a grey market store whose name I'm forgetting. Has some solid mid-tier brands at low to very low prices. It's on 57th between 5th and 6th on the south side of the street. And if you're looking higher end, nothing beats the service at Cellini.
Shoutout to Gabriel who was super responsive today on email when I proved that I don't know how to use the internet. I entered wrong billing information. Twice.
A few awesome pieces in the odd stock section for anyone interested. Kopped a pair of Carminas for a steal. These Bonafe shoes look lovely for anyone who's a 10.5 UK