Definitely make sure you have a reservation, if not, you'll be ordering everything from and sitting at the bar. Place was booked solid last night. Checked it out and was interested to see how crowded it would be and how late into the night people would stay. I was pleasantly surprised at how busy it was, how nice people were dressed, and how long people stayed. It's definitely a place you want to go to with a group of friends. I think this place is bringing people out who wouldn't normally come to Disney Springs, too. Or if they were in DS before, this is now giving them (adults without children) a place to go and have a fun night out while at at WDW.
Oh, and I was doing some people watching and actively seeing people get turned away at the door, too (in case anyone is skeptical that they'd do that). Sometimes it was for something as little as having drinks from other restaurants (no outside drinks allowed) and sometimes for dress.
You won't easily find the passage way from Edison to Enzo's Hideaway. In fact I can almost guarantee you won't without having to get some sort of assistance or following someone. The doors are not marked and it looks like you shouldn't be going the way that you are until you get to the other restaurant. For those that have been, the door is on the first floor near the bathrooms.