Yeah, I've got one of these (was supplied by my employer). The Pencil is useful for whiteboarding, sure, but I hate both modes of charging. It really feels like design went out the window when they were making these:
Take the cap off and plug its male end into the Lightning connector on the iPad. Now the thing is sticking out perpendicular to the iPad and feels like the two have taken over my entire desk's width, and feels really, really fragile. Like if I accidentally pick up one or the other the wrong way it'll snap the connector right off. Or...
Use the female/female connector to plug into whatever charger. It works, but it means at all times I need to track these two little 1cm bits of pencil cap to make sure I don't lose them.
It works, fair enough, but it feels like a design fail.