I had sort of a rough experience with Tannen's when I was in the City this past March.
After having a 10 minute conversation with the doorman (?) as to where it was in the building, (Note: you have to take an elevator up to a specific floor), we were met by the employees leaving the store for the day in a very stern and rude manner.
Despite the history, I'll probably never try to visit the store again.
Now Fantasma on the other hand.... its like Disney World. David Roth excused himself from a conversation he was having with a regular customer to personally perform a Card to Pocket effect for my girlfriend. Now, being a magician, I should have known the workings of this effect. But I was too lost in his personality and presence to even notice. Its magic shops like this one that remind us of that old brick and mortar that first got us started in this field. And I'd gladly go back.
You can't really miss it if youre in the vicinity. Its adjacent to Madison Square Garden.