I received my Spiderflex bike saddle this week and have been testing it out. Several days of commuting and plenty of adjustments have led me to the conclusion that it's just not going to work for me.
The initial intention was that, without the horn, the Spiderflex would completely eliminate the occasional circulation problem the previous seat caused. Instead, the seat changed my balance, put a lot more weight on my hands and turned an occasional numbness problem there into a more regular, nearly constant occurrence.
Lifting the pressure off my hands causes me to slide forward. Without a horn on the seat I'm pretty much sliding off. More weight on my legs means they are not only working to pedal but also expending energy to keep me in the seat. Wasted energy. I lowered the seat to try to mitigate this sliding-off issue but that changed the geometry of my legs, keeping me from getting the full extension.
I had upgraded to the previous Serfas Rx saddle from the Terry Liberator because the gel gave me more cushion for extended riding. The Spiderflex was a return to the more solid seat and I noticed it in 30 to 45 minutes. I would not look forward to 10 hours of that. In addition, the Spiderflex is has a fairly flat profile. Since my ass is not flat, this only increases the pressure on the ischium (the bottom "pointy" parts of the pelvis).
When I stand up on the pedals, to either take pressure off my backside or to better handle rough terrain, there is no horn for me to stabilize the bike by holding the saddle between my thighs. I don't like not having this control.
Another loss of control is when I take one hand off the handlebars. Because more pressure is on the hands, lifting one hand tends to turn the handlebars if I'm not careful.
The benefit does not balance out the negatives so I'll be sending it back.