As a mild Harry Potter fan I found this place enjoyable. I enjoyed the subtle references but liked how it wasn't over the top. They also have a LOT of coffee drinks so there's definitely lots to choose from. I actually really enjoyed their nitro with sea salt cream.
This place isn't cheap, but the service is top notch. When I ordered a drink and didn't like it, they let me switch it out for another one for no problem. The staff is really friendly and the service is really quick.
I'd definitely recommend this place for Harry Potter fans, and recommend it for coffee aficionados as well. If you're neither of those, you may be underwhelmed.