I've got several B17s on a variety of bikes. It's a fine saddle when your bars are almost level with the saddle. Nice and comfortable once broken in.

I had a Professional on my Mercian but it had a tear in the leather near the nose when I got the bike and lasted about 1,000 km before it was replaced. I have replaced the Pro with a B17N Imperial (with cutout) as I got a good deal on it. I don't have a huge saddle/bar drop. Both were/are more comfortable in the drops than the hoods due to their narrower width. Probably a better Brooks for a bike with more saddle/bar drop.

I have a generic CF/Plastic/Vinyl saddle with cutout on my titanium Eclispe. It is just as comfortable as the Brooks B17N when in the drops. It's not as comfortable riding on the hoods due to it's narrowish width. I again have my bike set up without a large saddle to bar drop, although when my slush fund allows I'll get a lower rise stem to drop the bar down.

I also have a B66 and two B72s on bikes with a very upright riding position. They are great for that. I'm a big fan of Brooks saddles.

One thing to note with Brooks saddles it that they tend to have less fore/aft adjustment available than modern shell saddles.