I feel like I should chime in here as I am a Pax and Volcano owner who has now been using the FF for one day now. Also I am taking everything but cost into consideration here so...
FireFly vs Volcano: There is no comparison when inhaling from a Volcano Bag vs the FF, the Volcano is much easier, tastier, and smoother. Only the first inhale from the FF tastes great, as where with the Volcano the entire bag tastes good. Inhaling a full breath from the bag takes an effortless 2-3 seconds as where the FF takes 10 seconds of slow inhaling (you have to really work for each one). Also packing and unpacking the chamber is much easier with the Volcano, as with the FireFly it is a bit more messy because of brushing the lid and the chamber. And the FF chamber is quite small, only enough for 3-4 inhales. The Volcano is a far superior vaporizing experience at home. But if you only inhale very few times a day, are looking for something at home, and don't want to deal with baggies, then the Firefly is your guy!
FireFly vs Pax: Let me start with an advantage of the FireFly. It can give you a stronger inhale of vapor than the Pax. The Firefly might be a better at home vaporizer when compared to the Pax because you can control the heat to individual inhales, and also each one is stronger. You can also use it better with less. I can pack the Firefly, and with the preheat method I can get 2-3 strong inhales. The first one being the best. The downside to the Pax is that you have to pack a full chamber which uses a lot if your gonna do this a lot.
Other than that, this is not a great on the go device, heres why. First it is kind of awkward to hold, it is not that great holding this big thing in front of your face for 8 seconds. The Pax is much more easier to hold, the FireFly is kind of awkward to use on the go. The FireFly chamber is really small, only enough for 3 inhales, and thats about it. The Pax on the other hand has a large one so you can sit and constantly use it for about 15 minutes or so, but the downside is you need to finish it once you start usually. The Pax batteries last longer too. The Pax is easier to unload and load too, and I think just as easy or easier to maintain. People new to the device can easily use the Pax, as with the FireFly, chances are a novice might not be able to use it right. In regards to draw resistance, since the Pax is conduction, it is constantly generating vapor, so all you have to do is lightly sip it out every few seconds as with the FireFly you have to work a little to draw the vapor out since the vapor is only generated when the hot air rushes by. The draw resistance isn't that bad if you use the preheat method. Originally I didn't have the button pressed down on some inhales and I didn't notice because you can't really see the glow in the daytime when it is in front of your face. So I didn't think I was getting anything, but I figured it out. I am still learning how to use the device which goes with what VapeCritic was saying about an "advanced technique".
Overall, I think the pax is the best portable and the volcano is the best at home experience. And with the Volcano the vapor quality, ease of inhaling, and density is far superior.
The FireFly sits in a weird space between the Pax and the Volcano. It is slightly better in just a few things when compared to the Pax or Volcano. Sometimes I just might not feel like filling a baggy and I think it's at those times when the Firefly will really shine.
I still don't yet regret the purchase as it is a fun device to use sometimes but still the best home experience is the Volcano with the best portable experience being the Pax. Maybe I will change my mind as I intended to keep testing it out and learning how to best use it