When Agfa went belly up in 2005, I got religion. Everything I used at that point was Agfa. Paper, film, developer. As a result I started studying chemistry. Years later, I prefer to mix my own to simply avoid a repeat of the past. My favorite film developers are Rodinal (which I have replicated on my own at this point, will post when assured it is good enough over years), Pyrocat-PC, Edwal 12 and 10, and Beutler's. The knowledge gained during the intervening years though is priceless.
I make my own paper developer as well, Ascorbic Acid and Phenidone/dimezone. Life is just that much more simpler. I no longer have to be tied to availability of some manufacturer's chemistry. As long as film and paper are made, I will be fine.