Butts are all different. I don't use anything BUT B-17s (got them on three bikes) after trying maybe 25 different saddles in nearly 40 years of cycling. I can stay on the bike for three or four hours without discomfort, something I've never been able to do on another saddle. But I have friends who've given up on them (that's how I got my last saddle, from a guy who hated it).
FWIW, a tiny amount of tilt seems to make a difference. Measure from the top tube to the tip of the saddle, then try adjusting that in tiny increments, just a millimeter or two. Don't try to eyeball it; use a ruler. Mine are very slightly nose up.
Do you have the heavy leather version, or the standard, thinner one? In general I think break-in problems with Brooks are exaggerated (mine felt fine right out of the box), but the thick ones do need awhile longer to accommodate your sit bones.
Don't overtreat them in hopes of softening them, by the way. Grant Petersen at Rivendell says Brooks recommends a THIN coat of Proofhide (Brooks' proprietary leather treatment) only once or at most twice a year. My oldest saddle is going on 20, and it's had much less than that. Still looks and feels fine.