I am looking at getting another Monarch in the 32-42mm size up to 16X. I have a BDC now, and thinking about a
Mildot or Nikoplex this time.

Any thoughts on what to get?

Monarch 3, 4-16x42, Nikoplex would be my preference.

Nikoplex. I for damn sure wouldn't buy the BDC...

Nikon offer's a number of choices that will meet your need. Plus, if you want to save some $ Nikon has their MONARCH 3 4-16 mildot reticle on sale for $60 off which puts it near $400.
Check out the link below for all their current long range specials. You might want to check out this site's Sponsor's to see if they can help you with your purchase too. If you have any question's drop me a note. Are you using Spot On to shoot your BDC retiucle scope?

http://www.nikonpromo.com/long-range-precision-1-16.php

I just got a Monarch 3 in 4-16X42SF in Nikoplex. It came with the XR turret coupon. I have yet to develop the load for the turret but am really happy with the scope. Got it for $399 at my local Sportsmans Whorehouse.