I've made a ton of small projects with them and so far absolutely everything has been perfect!
For me, what makes it the best choice is convenience: they've integrated the schematic+PCB editor (EasyEDA), the PCB manufacturing service and the parts shop (LCSC,
https://lcsc.com/) all in one. So you can make your schematic, make a PCB out of it, order it manufactured and order the parts for it so they ship in the same box as the PCBs. Yup, I'm lazy like that.
I've mostly used the "regular post shipping" method because I'm fine with waiting approx. 2 weeks for the package, so far not a single problem here, would recommend.