I opted for gel insert in my C&C solo, then took off with it without even a break in on a 10,000 mile trip over 17 days. I road up to 17 hours per day without any fanny fatigue at all. One thing with gel, though - it will heat up quite quickly when the bike is left in the sun for a bit. The dissipation of heat is pretty damn slow, so covering it, like when you stop for lunch, is highly recommended.
What if the Hokey-Pokey really is what it's all about?