I went with a set of new single motor Carvon. Mainly to save weight. I went with a new one partially to support the cause and also to get the latest version.
Carvon, Hummie, and Jacobbloy are all pretty much just guys building these things in their garage. So unlike a big company where there’s a ton of testing and hundreds of thousands of dollars invested before a product gets released, these are constantly being improved upon and we are in many ways testing these products out for them. There is of course pluses and minuses to this. On one hand, these products all have some room for improvement, but on the other, you get to be a part of that process. So your feedback really matters and you have impassioned people working with you every step of the way.
You’ll save some money if you go with a used earlier version, but if you have the cash, it might be worth it to go with the latest and get the tech support from the guys who are building these things.