I'd been using PCBWay and really enjoyed working with them. They're fast, friendly and helpful. They have cool videos on their website showing the fab process. They'd also been very fast, until these boards. They were made right before Chinese New Year, and they hit several snags leaving the country and entering the US. They hit Portland right as a snowstorm came in, and they spent a couple of weeks "held due to an Event Majeur." During this time, I got frustrated waiting, and so I re-ordered (after fixing some bugs I'd noticed) from JLCPCB. That second order arrived the same day as the original boards, so I mostly used the 2nd set.

I still order from PCBWay, but for 4-layer work, JLCPCB seemed a bit faster and cheaper, so I went with them for this latest order.