Apologies if I missed this somewhere, but I couldn't find much.
I'm about to make the jump into a G19 with an RMR, and while I'm still debating direct mill or MOS, I have a question about direct milling options.
BUIS, in front or behind optic? Any reason to prefer either? Pro's con's? I've read elsewhere that putting the rear sight in front of the optic will keep it from obscuring the optic window / red dot and help protect the glass on the optic. That makes sense to me. But are there any downsides?