I got it very recently and only made the initial charge so far. I've been using it for a total of ca. 2 hours (two one hour runs). Their FAQ and manual says that full charge should last 26 hours. That means that someone running once per week for one hour should recharge it twice a year… which to me sounds like not much at all.

Exactly.

Honestly, given how rarely you should have to recharge it, I think it'll be a long time before the battery dies. Even if the maximum charge reduces a bit with time, I think that would still be more than enough.

I don't have any experience with other devices, so I can't compare. This product feels very light. I didn't feel any discomfort at all.

I rather like to think that Zephyr are smart to provide them.