Yeah, we've found that 3 mil lines/spacing is preferred (i.e. cheaper) than micro-vias. This is especially true in high-volume production overseas. As micro-vias become more prevalent, that may change. Originally posted in cdnusers.org by dgstan
At first, I was reluctant to use them (I thought it would be more difficult to design with them), but after doing umpteen boards with micro/blind/buried vias, I practically beg marketing to let me use them.