Selle SMP TRK model for me. This saddle is less comfortable than the Brooks B17 after an hour or so of riding. The discomfort is under the sitbones, due to lack of blood flow. The discomfort disappears completely within a few minutes of getting off the saddle. The B17 was never uncomfortable for me, even when brand new, but I was concerned about long-term damage to the nerves of the genital area, causing eventual impotence. As I wrote elsewhere, this damage is supposedly like the fraying of a multi-stranded rope. You notice nothing until the last nerve strand is broken, at which point the damage becomes very evident in the form of impotence. It will typically take years for the broken nerves to regenerate, or they may never regenerate.
While sitting on the Selle SMP TRK and reaching my hand underneath, it is pretty obvious there is a lot of soft tissue hanging down into the opening in the center of the Selle SMP saddle. While on the B17, that tissue would necessarily be compressed in some way. Perhaps not damaging in my case, since the B17 was never uncomfortable for me, but based on that multi-stranded rope theory of damage to the nerves, I don't want to take the risk.
My comments re comfort of Selle SMP versus Brooks B17 are based on one tour of about 1200 km for the Selle SMP and eight tours totalling over 20,000 km for the Brooks B17. For just riding about town, it makes no difference, since the Selle SMP takes an hour or so to get uncomfortable.
The Selle SMP TRK also weighs less than the B17 and is vinyl coated so doesn't have to be protected from rain. There are also some leather coated Selle SMP models. These are less wide than the TRK model, and so might be more or less comfortable than the TRK, but the leather coating means they would have to be protected from rain, which is a downside. The leather models also cost more. So I'm not planning to switch from the TRK anytime soon.
There is a tendency for some people in the English-speaking world to talk of Selle saddles. Selle is Italian for saddle and there are many Italian makers of bicycle saddles which include Selle in their brand or company name. So be sure to write "Selle SMP" when referring to that specific company/brand name.
[edit to note that b17 was never UNCOMFORTABLE for me]
