I'm hardly an expert but travelled UK-Aust last year and am about to make the same trip again this year on MU in J. Their A350s have the suites with doors and although the whiole experience is below that of say QR or BA, they still offer a decent product, especially when you look at the price.
The Cons: Website is useless and even when you manage to get English, it still is clunky and I am yet to be able to actually buy a flight on it. I actively go to a OTA so at least I will have someone to speak with if something were to go wrong. The food is OK, especially the Asian selections, the western food is so-so. And a poor choice of wines if that bothers you. Enetrtainment system carries very few western treats and many of them are quite old. Take a laptop or iPad full of stuff top watch.
The Pros: Well, the price for a start. From London, it is barely worth trying to position yourself for an ex-EU flight as the money saved is simply not that great, so less reason to risk things going wrong on that front. The seat is fine, which is what I want to go in J for. Being able to sleep, and that is simply not a problem. Service is good, but not superb, but certainly pleasant and nothing to really dislike. Lounges in PVG are huge, have showers and sleeping areas and food. They are part of ST, so although I would like to credit my BA account, at least the points aren't toally wasted as I can use them with VS.
As far as I am concerned, the money saved is substantial and the result is similar - a sleep, food, comfort and and decent experience.