I have been using the firefly 2 since the beginning of June. It is a solid vaporizer as long as you use it the right way. Although you can break a up a bowl pack into multiple sessions, I found that it is best to finish a full bowl pack in one session. The reason is because this device works best when it is squeaky clean.
I get 8 solid clouds and great flavors with flowers on the medium setting with each session but I clean it after each session. A dental tool, isopropyl alcohol, and a paper towel is all you need to clean it. Clean the bowl part with alcohol and use a dental tool to clean around the bottom edges of the bowl. Also, clean the lid, chamber, and mouth piece. Just a quick swipe of the paper towel is all you need. I removed the screen but if you keep it in, you need to clean it after each use. This is important to remember. All parts need to be clean in order to get the best vapor.
It is also best to break the bud up with your fingers or sharp scissors. Stay away from using a grinder and pack it full. Stir after every other hit, this is where the dental tool comes in handy again. The first and second hits will taste amazing and get a decent vapor. Stir after this hit and gently pack it down. The third and fourth hits will light you up. Stir again and pack it down a little bit tighter. The fifth and sixth hits taste decent but start to decline in quality. Stir again and pack it down tighter this time. You'll still get two more hits with visible vapor.
I keep mine on the charger at all times and have never had the battery run out. Out of all things, I'm not worried about it if this isn't optimal for my battery life. I can always buy a new battery if it is an issue.
Couple of things I want to point out. The clip on the left side of the mouth piece on my firefly 2 broke off after a week of use. I emailed them to see if I could get a replacement and they said that they were out of stock. Looks like they have been out of stock for a while now. For a vaporizer at this price, I would like to have access to necessary accessories if one fails, breaks, or gets misplaced. Also, twice the vaporizer wouldn't turn on when I knew the battery was charged because it was sitting on the charger with a solid blue light. I had to switch in the secondary battery to turn it on. Once it came one, I was able to use the original battery without a problem. Almost seems glictchy. Both of these are not big issues and the quality of the vapor is makes this my favorite portable vaporizer. I have a Mighty, Volcano, Haze, and Firefly 2 so that is all I can compare it to.