nachum, let's start with your last question first.
Has Martin de Candre changed their formula? I don't think so. I've been using several jars of Martin de Candre on and off for the last five years. The oldest jar performs just like the newest.
Have your tastes changed and are you doing something different? I suppose these are questions you'll have to answer on your own. But let me mention that when I first started shaving with a double-edged razor I was a tallow-only shaver. I loved the extra protection a thick tallow lather offered. I needed that protection because my technique with the razor wasn't up to snuff. Over the years my skill with a razor has improved noticeably. I no longer need a heavy tallow lather to protect my hide. In fact, now I find that tallow lathers are a bit too protective. In other words, I can't get as close a shave with tallow as I can with a vegetal lather. And there's this too: vegetal lathers generally smell lighter and fresher than tallow. Now, do vegetal lathers dry the skin? Yes, at first most do. But as my skin gets older and starts to sag, I don't mind that dry and tight finish. It's like having a free fifty-minute face lift. And once that dryness fades, I find Martin de Candre's finish to be one of my favorites. It's plump without feeling oily or waxy.
So, what's this all getting to? My tastes have changed because my technique has improved. I suspect yours have too. I now use vegetal soaps most of the time. Among them, Martin de Candre is a clear favorite.
. And the great thing is - if you don't like it, you can send it back. [fat chance] Barbershop Quartet has stunningly good. 
