Just to add another opinion. My sons new bike has Microshift Advent fitted.
My intial reaction was to bin the lot and just put XT on there but it's a 24" bike and he's going to grow out of it, so I did have that to consider.
In truth, after (only) 100km, I can't say theres been any problem with it. It's his first geared bike and he's certainly not complained about shifting performance and he's been quite brutal with it, as you can imagine. Longevity wise, time will tell.
It's not BSO grade gear, definitely not. I'd say it sat around Deore or just below in terms how it feels in the hand. Weight wise, however, is another story. I believe the rear cassette, for example, is lighter than XT, even though I'd doubt it would last as long.
I don't think Microshift is fully interchangeable with Shimano, but I am open to being corrected on that?