I've had one for about two thirds of a year now and have to voice mostly disappointment. I bought it to address a specific condition, which was the fact that the leather brooks saddles rise at the back end where my sit bones are and unless I tip the nose upwards more than is comfortable I slide forward as have major pressure on my perineum area. I think that is the result of the fact that I don't peddle as vigorously as I used to. When I used to ride harder, I had very little weight on the seat. Now I wan't to sit much more upright, and take the weight off of my arms and neck (my neck hurts at the end of any ride longer than an hour). Thus in order to do that I need to point my saddle up and I have good comfort, but only in a very narrow range. If I bend down a bit or move my hands more forward - agony.
So looking at the profiles on the cambium saddle it seemed not to slope downwards forward of where I have my sit-bones, and in fact that did result in relieving me of my primary problem. But several negatives have come with that one improvement. First the B 17 has been made more narrow. The cambium is 162 mm wide versus the 175mm width of the leather equivalent. One step forward - one step back, for me. It does not breathe as the natural leather does, but I guess we all could deduce that. Brooks marketing tell us "immediately comfortable" which turns out to be, in my experience "immediately tolerable, never your own perfect shape". Lastly, and this was quite a surprise, I find that there is a bit of a trampoline effect and feeling as I cycle.
When I ordered and received my Nomad back in 2011, I was very happy with all the details of my order except three things. One's too trite to type about but the two others really were disappointments. Firstly the front wheel was built to shoddy standards. It had so much runout from side to side it required the breaks to be adjusted as wide as I could get them while still having enough to stop the bike. Secondly, and more frustratingly the mechanic who built up my bike cut the front fork to how I was measured despite my getting assurances from the sales end that it would not be cut, as per my wishes. That has become a deeper problem over time and I can't move the bars up high enough to stop the pain in my arms and neck and it impacts the seat comfort to an extreme degree. I'm not getting younger.
So the tried and true real leather B17 saddles (of which I have three - all with slightly different shapes right out of the box - as should be expected) I find the best comfort, but due to somehow either not fitting my Nomad well enough, or being too far out of a solid healthy state for cycling, I find the leather seats very good in comfort in an unacceptably short range of posture. I cycle with the tip up so I don't slide forwards and with my palms a bit extended upwards. I can do that for about an hour. Replacing the leather with the new plastic Cambium works ok, but it's what I'd sum up as an underwhelming sideways step and the bounce it give is unpleasant for me.
Now I don't mean to whine or sound disappointed with my bike in any way. Over all I'm a proud Nomad owner who could (and probably will) buy a new Nomad fork and try another few handle bars. Rather I took pains to describe my particular circumstances - to illustrate how particular and personal my problems with the B17 in tried and true leather is. I think the fact I ride the better suited For most more "normal" cyclists I fully recommend the old way - and forget the slick marketing as we take a couple of steps forward and just as many or even more backwards, with the Cambium range.
