It took me 800 km to break in my first Brooks. My second was still not quite broken in at 1000 km, so we did the washcloth trick and it was broken in within a few km. For my third, we did the washcloth trick after about 100 km, and it was broken in within a few km.
A couple additional comments ...
1) The saddle should never become soft. It should always be firm ... hard.
2) If you don't want to do any of the break-in tricks (and the ONLY one I would advise is the washcloth trick ... do not do any of the others), go for a ride in a downpour.
A Brooks saddle is worth being patient for.