Don't know when you went, but we were pretty disappointed, unfortunately
They had a MMr, DP Pro, STh Pro,
CC, GB, MBr and an A:IQ when we went. Unfortunately, the MBr was out-of-action with a really simple problem (snapped rubber on slingshot) and the server upstairs had no idea how to fix it. So, there were six working machines, the GB was filthy and apparently the MMr wasn't in great condition either (although I didn't play on it).
The A:IQ was upstairs with a bunch of Japanese arcade machines (e.g. dance, fighting) and they seemed to be getting all of the love - both in terms of the number of people playing, and also the number and condition of machines. We were downstairs playing pinball for nearly two hours and, only in the last ten minutes, did anyone else come in.
It was better than nothing, but it wasn't even close to Flip Out...
It certainly wasn't as good as it looks on the website...
We were a little sad as we'd cycled two hours across London to go there.