I found myself going back to the Novo 2. I've since upgraded that to a Novo X, which has a display and a wattage control range.
I liked the Caliburn, but preferred the Novo. Also, I definitely had some quality control issues with the Caliburn. It just randomly wouldn't drag sometimes. And sometimes the light would flash green which is supposed to indicate good battery life, and in actual fact the unit would be empty, so it was hard to know if it needed charging or not.
I do like the look of the new Uwell Koko Prime. I'll probably pick one up at some point. And there's also an upgraded version of the Caliburn called the Caliburn G I think.
Aside from the QC issues I had, I'd say the original Caliburn and the Novo 2 were pretty close. But the Novo X is a significant upgrade.