I've been wondering about that myself though.

I know our parts change a lot as the years go by. But back in the day, back before Georgena Terry invented the cut-out, I could ride all day on the tensioned leather saddle on my first diamond frame bike. When I went to plastic shell saddles, I thought I'd died and gone to heaven the first time I rode the one with the cut-out in the shell but not the cover ... but it still was gel, and it still wasn't as T-shaped as a tensioned leather saddle.

I wonder how badly I really do need a cut-out if the saddle fits me properly. That saddle is likely too narrow for me, but gawd that shape is appealing.