Think I'll give it till about the 500 mile mark before I do something too radical. Got the conditioning stuff that Brooks sells and am using that for now. I'm seeing a bit of progress but still far from the comfy, glove like fit that people rave about. Toriaizu, gambarimasu.
The first Brooks I got last summer, the proofhide didn't seem to absorb very well on its own, but then I tried leaving its underside in direct sun, and that coat and another soaked right in. The second, a xmas present, I used the living room heater--a couple generous coats of proofhide soaked in each time. (not too close, but enough to be warmed).
The Brooks models vary in hardness/stiffness, and so there's probably a range of break-in times, too. The B17 I got first seemed fine from the get-go (tho it's on a seat post with a built-in shock). The Swift is certainly harder, but it's also a road, rather than touring, design. I'm on my 3rd repositioning, and think I've just about got it, tho might try it a tad further back at some point. Didn't really even think about it on this morning's ride, tho.
If you happen to have gotten the Team Pro, Brooks says that's their hardest/stiffest model, and unless your rear happens to match it well right off, it probably will take longer to break in.
Back in the day I used to work in the woods and our most prized possession was our cork leather boots. They were handmade and stiff as a Bull's you-know-what. Until they broke in, they broke you in! Conditioning process was as follows:
Fill up a tub with hot water and a little soap.
Put on the boots and soak in them for at least an hour.
Go to work a half shift. Change out your socks (we always wore wool).
When you got back home, then rub in lard thoroughly. Alot.
Pack the boots with newspaper.
Repeat the process - generally it took only 2 or 3x to get the boots worked in perfectly.
After that - maintenance was simple:
Pack with newspaper when they were wet.
Re-apply Mink Oil, Snow Seal or some top secret mixture. My grandpa used to make his 'boot balm' with at least 10 different things - I'll never know for sure - but it did have Beeswax, Mink Oil, lard and other stuff. The leather remained supple, yet not too soft for the heavy duty of scrambling over timber all day. The old timers weren't too fond of Snow Seal, but I sure liked it. It sealed the boots without making them overly soft and requiring replacement. (About $1500 in today's value).