I DO try to distinguish between tours and sit downs when discussing things like that, so I didn't want to touch the topic in my original post.
If Phantom comes back and looks beautiful as ever but the technology is newer and affordable and efficient to run, resulting in a more streamlined crew and there are several fewer actors in stage... well, I wouldn't complain a lick. If a wagon is a foot smaller, I won't be bothered. If the descending Angel goes away and is replaced by an upstage Angel set piece like I on the world tour, I will notice and I will miss the effect if I see the show, but it won't shatter me. If they cleverly cut three musicians, I might notice - but West End is more free with digital augmentation and it can be well done.
If the Chandelier doesn't flicker and rise at the overture and then fall and crash to the stage - or it does so at a MORE comically slow pace or the orchestration is significantly reduced and notably canned, THAT would be a death knell.