My report back on the RBR leather saddle. At least based on my experience, I'd recommend against getting it. If you want a leather saddle, get one from a known quality source. Or at least get one without springs (which make it more difficult to maintain tension in the leather, as the metal plate which is riveted to the rear of the saddle can rotate forward on the springs, so the leather sags under the sit bones where it is not supposed to).

My saddle came with improperly-assembled (or poorly-conceived) tension mechanism, that I was able to tinker with and modify until I had a setup that could actually increase tension through the leather.
However, even then, I couldn't increase tension meaningfully because the springs would just flex and allow the rear metal plate to rotate forward. This allows the leather toward the rear of the saddle to sag markedly, and my sit bones feel like they are sinking in just in front of the metal plate at the rear of the saddle. Note that I'm 6'5", 200 pounds, but I think that this would happen to a lighter weight rider.

Sure the saddle is rideable, but not remotely comfortably. Not like a leather saddle is supposed to be (and I realize that the leather is supposed to be very hard until broken in).
I suppose I could lace it, but I'm not sure it's worth the trouble.

This makes me curious how sprung leather saddles work to maintain sufficient tension. With the Brooks B67, are the springs just a lot stiffer (particularly toward bending) than this RBR saddle's springs? Or does it depend on lacing?

Here is my thread in the mechanics forum on the tension-bolt-assembly setup.