This is a good illustration of the wrong way people think about percentages and riding. While 100 miles sounds like a long distance, and it is, the real distance that's important here is the distance between two finishers of that ride. If you could improve your speed by 1/10 of 1%, you'd finish 528 feet ahead of someone who other than this change was riding exactly the same speed as you.

For "normal" people who aren't in hard-fought bike races, but rather just out riding for our own pleasure or improvement, the 1/10th of 1% isn't going to make a substantive difference in our times and whatnot, but who cares? If we're riding for our own pleasure, then any feeling of pleasure we get by having better gear, improves our enjoyment. If that's what we're riding for in the first place, then it's mission accomplished.

Personally, I'm gearing up to do my first wheelbuilding project. I've decided to use Sapim CX-Ray spokes, despite the cost. Regardless of any weight savings or possible aero benefits, part of me just wants to feel like I've got a "cool" wheel build. It's my money, so if I get what I want out of this build, what's the problem? Is it "worth it"? Well, apparently so, since I've considered the price options and still decided to go with the CX-Rays, and my own opinion here is all that really matters.