I've had a Firefly since November and love it. Only problem has been battery life (of course). One of the two I originally bought has always been crappy (6 or 7 draws max) and finally just broke. I spoke to (Firefly) customer service and they sent me a new 770 battery for free and oh. my...
I have a FF and my mom has a pax1 (that I borrow indiscriminately). They're both great. The choice really depends on what you want it for.
To me, FF is a home use on-demand vape for one or two people. I spark it up instead of a pipe. The pax is much better for outside the house and groups...