ya the speed of pcbway is surprising i would say.
thanks for sharing EYG. 2% is pretty high. i noticed if you do panels on pcbway you have an option to accept panels with error boards in the panel or only accept perfect panels at a slightly higher price, but i wonder if you did that what the actual % of bad boards in the panel would be.... probably only one way to really find out...
here i post some pictures of pcbs done at different places for you:
Bittele/7pcb bare pcb, 4 layer, uses 6/6 spacing but bittele will go down to 4/4 iirc.
same pcb bottom view
same board with pcba (from Bittele, pots soldered in house)
Almost the same board from itead, with pcba, with internal short somewhere....some parts have been manually desoldered/soldered to look for short, c32, c33 for example.
4 layer 6/6 mil spec from pcbway, no blind/buried vias.
same board as above bottom view
V scored panel from itead, 2 layer 6/6 mil spec