This is some very helpful info @Vernon Barry. I'm printing at a 1/4 ratio now, if I understand you correctly. I print at 0.1mm layer height with my 0.4mm nozzle. My results have been great. I've printed that way for a while. I did clog a hot end this month and I couldn't seem to fix it.
Anyway, I appreciate the bit on the ratios. I wish I had that when I got started because it would have saved me a lot of trial and error.
I wouldn't mind trying the fancier nozzle. It makes sense that it would be better than a straight bore and I would be very happy to be happy to print a little bit faster.