Lauffray
Invisible Cities
Agree that you have to find your own times for Xtol, which is great for pushing in my experience, I've done 400 @800 and @1600 with a variety of films and they always come out great. My personal recipe is do regular agitation, and do the last 2-3min "stand", that is no agitation. From my highly unscientific tests, I find the shadows develop nicer