Very good room. If anybody is fed up with Potter rooms - keep calm, this isn't one. It has very nice set design, high production value, nice puzzles and some of them are quite original. We really had a lot of fun there. One aspect of one puzzle was super confusing and it didn't make sense at all to any of us even after GM tried to explain it, but fortunately we could have just ignored it and solve the puzzle without it. If I recall correctly we escaped without hints with not much time to spare.
Minimum number of people declared by owners is 6 people, but I think it should be physically possible to do it with 4 people. Maybe if you really want to do this room then contact the owners and see what you can get. By the way, this room has private booking, not public booking as indicated here.
As kind of a pioneer of writing reviews on USA version of lockme let me make use of the grading scale adjusted to explanations associated with them. I grade it 9/10, I think "This room was great - it had great puzzles, theme and service and it surprised me in some way." describes well our experience, however on Polish site where grades are highly inflated, I would rate 10/10 ;p.
In my new rating scale that I decided to adapt (1-horrible, 2-ok, possibly flawed, 3-good, worth doing, 4-very good, 5-extraordinary) I grade this at:
Set design: 4
Something original: 4
Did I have fun?: 4