The three star review from Quentin Letts just makes me think they paid for the reviews. The general word of mouth (and not just on here) has been quite negative, and this is the kind of show that Letts would despise.
"its unfettered Britishness is a welcome change from all the American musicals in the West End" shows his maths is as suspect as Nigel Farage. I reckon there are around 14 British shows at the moment and maybe half a dozen US imports. Just imagine all the Eastern European shows he'll have to put up with when the 490 million Bulgarians arrive.