I haven't found a cutout or channel to be all that helpful for me. I'm one of the Brooks saddle converts ( www.wallbike.com ).

A firm, unpadded saddle that is wide enough to completely support my sitbones and with an abrupt enough transition from nose to wide part does more for me than any channel or cutout.

I had the Sefas Niva ($40 with a sun face on the seat) which was ok. Switched for a Brooks B67 and am very very pleased.

The wadding chamois is a definite issue. Nanci posted some great comparison pictures of chamois. I'm happy with the sculpted non-bunching style.