I've just stumbled across this thread, and as a Chadwick user in the UK, I feel obliged to reply!
First of all, it's true that Britain lacks a pizza tradition like the US. It's also true that there is a lot of dreadful pizza available in the UK, typically coming from fast food outlets that also do kebabs and burgers and cater mainly for drunken teenagers. That said, good pizza from small, artisan pizzerias can be had in any major city in the UK. And we probably visit Italy more often than Americans do, and get to sample the originals. I notice this forum is obsessed with Neapolitan pizza; I prefer the Roman variety, which is much thinner and sparingly topped with just tomato (rosso), or oil and salt (bianco), or courgette flowers and mozzarella. You almost never see meat on it. Three million Romans would agree with me that it's better than the puffy version of pizza in Naples. Though, to be clear, I love both.
As for the Chadwick, I think the doubts expressed above are spot on. It doesn't cook pizza evenly and doesn't reach the temperatures claimed for it. It is overpriced. However, it's better than cooking in a domestic oven, and given the climate here in Britain, outdoor ovens are not much of an option.
Two questions based on the discussion above: 1) what's the difference between a NY-style pizza and a Neapolitan? 2) where can you buy a Blackstone in Europe?