So after 25 hours, the speakers ( with my old metalized polypropylene capacitors in the midrange) sound much like I remembered. Very fast, better transients and more separation, however a smaller soundstage and they are not as musical or involving as the Clarity's they replaced. They are still a bit leaner than I remember, but they were always leaner than the Clarity's. Maybe the solder connections are still in need of burn in, we will see. As with many things in our hobby, some recordings sound better with each cap and about 20+% are not as good. I may also try some VH Audio ODAM caps in that position, as reccomended by grannyring. Hopefully I'll get the speed and transients of the mpp's with better musicality and body.
On that note, does anyone have a reliable method of buring in caps before placing them in the crossover? I've heard that the ODAM's take 200-400 hour's for their sound to mature.