To give some context, I bought the Millenium 12" splash, 14" and 16" crash on a budget for a bar band I joined, to use with an old entry-level Pearl kit I picked up for 150€.
Getting three B20 cymbals for about 100€ is amazing considering most cymbal manufacturers are taking us for a ride these days (pun intended!).
I think they sound good live (they crash well, cut through nicely and have a short ring with inaudible overtones). I also get the feeling that they aren't so cheaply made that they're going to be particularly susceptible to breaking. I'm a light hitter though, so your mileage my vary.
IMO they sound better than the Meinl HCS and Sabian B8 that came with the kit - I'll be selling those. For studio recording I'm not sure how the Milleniums would hold up though.
They don't look great on very close inspection (they're only machined - not hand finished), and the hole on one of them isn't quite perfectly circular.