The firefly performed well on my weekend trip. I'm still on the same battery since Thursday with light daily use of 1-2 sessions with a friend per day. I did have an odd battery incident that sounds similar to what others have mentioned. On Saturday I went to use the FF2 and it was unresponsive. A simple re-seating of the battery got things back in working order. I'm still on that battery, so I know it wasn't low on juice. This has me wondering if people's batteries are actually running out or just hitting this bug. I'm currently getting 4 blue blinks and have full battery in the app. I've never seen otherwise, though. Heavy-hitters may have issues with battery on this thing but moderate users should have no problems. EDIT: Thurs, Fri, Sat I used medium heat and Mon/Tues I used concentrate. Last night's concentrate session got things pretty hot.
The last few days I've been pressing rosin and the FF seems to handle it very well on concentrate mode. I've never used concentrates before, so nothing to compare it to. Not sold on rosin for regular use, but it is very easy to transport and quite tasty.
Regarding the filter in the mouthpiece, I can't understand where many of you are coming from. In my unit, there is no way that it is the most restrictive part of the airflow. There is virtually no difference in pull resistance when its in vs out unless the lid is off, whereas taking the lid off with the screen in seriously opens up airflow. Second, IME, increasing the airflow is the last thing you want to do for cloud production. I can't help but think you guys are witnessing other variations in your technique/materials. At least in my case, if you are pulling hard enough that you feel the flow is restrictive, you are pulling too hard. You need to self-regulate to get the best result. Otherwise it sounds like there is wild sample variation and we are using practically different devices.