Any information about the mods from Vapor Moon?

[Freyakat]

I was impressed by the looks of the Vapor Moon mods, and that you can have them customized to a degree. I want to get a mod, but I also don't want to throw $$ out the window.

I like to hear about someone's personal recommendations, should I go with the 5V, the 3.7/6V, or the VariVolt option? I'm not into tinkering so much, so the VariVolt is probably a no go.

Thoughts?