Still fighting with bits, feedrates, etc. But making useful prototype boards with it now.
This was done with a 60 degree .007 engraving bit and a #66 drill bit, 10 ipm feedrate on X/Y and 5ipm on Z (was breaking smaller drill bits going faster - using 1/8" shank drills in a 1/4" chuck with an adapter and there's a bit of slop in it that doesn't show with the 1/4" shank engraving bits), a Dewalt Trim Router (30k rpm or so? haven't measured).
My engraving bits seem to chip/dull pretty fast so far - tried ordering an Amana InGroove from ToolsToday, but they sent the wrong bits and don't respond to emails. Another day, another distributor :)