When PCBWay stopped accepting PayPal last month I tried JLC and I have to say, their quality was impressive and the price was a little over half the PCBWay quote. Certainly worth shopping around with your gerbers. Might be an interesting write up comparing quality and price from the leading Chinese fab houses for the same board.
Only done very small 2-layer boards for hobby projects, but it's crazy that you can get custom PCBs made and shipped from China for <£10
It seemed like it might be coming to an end when PCBWay suddenly had no reasonable payment options, but JLC has been great so far (and I believe PCBWay has credit card payments sorted now?)
(Just wish I had far more free time to spend on hobbies, there's so many possibilities with 3D printing, microcontrollers, and custom PCBs now all so readily available)