Simple answer to your question...No. My longest lasting soap is not my favorite. That correlation would be most unusual.
I'll be "piling" my winter soaps come May....won't be close to finishing any with the possible exception of the TSD Lanolin w/Russian Leather.
with 12 soaps in the rotation they all seem to last forever. However I have yet to see any visible wear on my jar of Tabac that I've been using for about a year (to be fair each soap gets used about twice in one month). Right now my favorite soap is RazoRock Don Marco, it has an amazing orange citrus scent and great performance.
MDC is definitely within my top 3 of shave soaps. I am pretty certain unseen French nymphs sneak into my shave den and magically refill the jar after each use. It never dissappears