Feels pretty good. Initially a little firm but seems to have broken in a bit already (less than 100 miles riding). I had ridden a B.17 Standard in Portland for a while but never really loved it, so far the Narrow seems to fit better. I purchased an Aardvark waterproof saddle cover from VO and some leather proofing. The rails on the saddle do not run parallel the entire length (for most Brooks, it seems) which means if you require a good deal of saddle setback then there is a chance you may not be able to achieve it without switching to a different seatpost with more offset.
The sad fact is that my Gitane “Le Tour de France” is an older frame with plain straight gauge tubing and as such has a 26.4mm ID for seatposts, which means selection with 30mm offset are very limited. Kalloy makes an “Uno” model with 30mm, the one pictured above is the “mid-range” Kalloy model that is welded as opposed to bonded, single bolt alloy clamps with 25m offset. The 30mm offset model appears be a bonded head model. I’m not a fan of bonded clamp heads. I had one fail during a cyclo-cross race years ago up in Sea-Tac.
Single piece seatposts, ideally with two bolts, are desirable though few 26.4 posts have what I need. Most Brooks (in the last 100+ years) were used with non “micro-adjust” clamps, whereby the post and clamp head assembly are separate pieces. On sportier models like the Swallow, I think the rails run more parallel. If I had 5mm more of adjustment I’d happy. Custom made seatposts are not cheap. Or you could cast or CNC machine a custom clamp that deals with the angle of the rails. I’m just going to keep riding it and see how it goes.