Question for the Brooks experts: what is it exactly about each model that makes some more suitable for bars lower than seat position (what some people call "agressive") than other models? By looking at the varies saddles, I see the differences in overall width in the rear of the saddle, but don't really recognize any differences on top towards the front of the saddle where, different, uh..., accommodations are needed when in a more leaned over position.

So...what is it about the swallow and swift that makes them better for a more leaned over position? I ask because if it's just something that one can get by "butchering" a b17 or b17n or a pro, then i'll buy one of those and give the extra money i'd have spent on a swift or swallow to charity (or my local bartender). If it's something that is intrinsic to the design that I'm just not seeing, then I'll buy the more expensive models.

I wish I had side by side photos of all the models on the same seat post to see their comparative profiles from the side...

(FYI, 6'0", 160 lbs, 40 yrs, and my bars are about 2" below seat level)