I've used PCBway a *lot*. I'd say I've easily done 20 designs with them, including a handful of PCBA of ~100 units and a larger order in process now. Everything I have done has been two-layer, mostly leaded hasl but also lead free, enig, and a couple with 2 oz copper. I use the 6/6 rules option, but I work really hard to only get close to that minimum rule if I really, really need to.
I don't have stats, but I feel like there are usually a couple extra boards in my orders. Of all the board I had made there I can think of maybe one that was straight-up broken when I got it, with a broken trace.
My assessment of their quality is that it has been "fine." I've noticed slight variation between orders, but nothing that was unacceptable. I wish the silk was higher resolution, but other than that, no issues.