I'm inclined to keep my one Elcon for dual J plug usage and as a backup for a little while, but only for long trips. The current version is a lot more reliable, and particularly the failure modes have all been reduced to controllable modes that still deliver power so you're not stranded.
Long trips deserve reasonable backup solutions. For a Zero, a spare belt is the main concern, and a backup charger seems like a close follow-up. Both types of failure are hard to recover from quickly if a dealer or experienced technician are not nearby. Chargers are more costly to ship, too.
The only concern with a charger is mounting it in a convenient and secure way. Right now my best option for the Elcon is to set it upright against the front of my top case and use straps to secure it inside a waterproof duffle that opens up to charge. But I don't have a Power Tank, either, so my Supercharger goes there...