The Firefly was one of the first on demand / burst vaporizers to get the job done right. It was fast to heat up, produced a bunch of vapor and tasted good. When used properly, it managed to get you that on demand experience while still avoiding combustion.
The Firefly 2 was released a few years later, same great vapor in a more compact unit with a longer lasting battery. A good upgrade from the original more heavy larger Firefly.
Summer 2019 saw the release of the Firefly 2 +. Basically a Firefly 2 but more compact, more affordable, better air flow and a longer lasting battery. A nice upgrade, especially for a vaporizer that costs less than its predecessor.