Neil, can you please stop making excuses? Funland is supposed to act as Electrocoin's Stern showroom and, indeed, it works that way (it sold me a Godzilla Prem). Thus, you would hope, if not expect, the gameplay at Funland to have some resemblance to a typical example of that pin. Ideally, you'd want the first examples of that pin onsite in the UK to play better than an average example - to aid sales.
I've played two different Rush and two different Stranger Things on location, and haven't noticed significant differences in the gameplay between Funland and anywhere else. Your pins, and the Funland pins after a tournament you ran was held there, did play better - but, ideally, pins on location shouldn't need extensive tinkering by a semi-professional to be half-decent to play.