@Shit Snacks Unless you like combustion from something with a battery in it stay away from the firefly. A friend let me use his for a week because I was looking into the firefly, needless to say after a day with it I just rolled blunts for the rest of the week. Also online there are many credible reviewers that call it out for the Combustion issue, plus I was able to tell the difference on many of the videos, smoke looks way different than vapor.
Updatability has been built into the Haze unit as they have planned on it being something that can change/grow with the company. Haze is very committed to staying on top of their game and has assured us that FC members are the go to crowd for ideas/suggestions/comments.
I would still get it even if it was just for Herbs, why....well you already answered some of that. You get two chambers, can pre-pack cans for pop pull blow n go situations, you get an extra battery right off the bat with your new Haze plus you can get more too. It is easy to use has two different mouth pieces, easy to clean and as far as looks stands out among the others.
O.K. here is the final thing, you mentioned getting extra batteries, extras are always a good thing that way you are always prepared and do not have to wait for a charge. As far as is it worth it, we all value things in our own ways. Here is the run down on what I got when I ordered my Haze. Items are as follows: Haze Unit, 6 cans total, 2 more extra batteries (4 total), 2 mouth pieces, cleaning brush, loading/stir tool, wall charger, 4 screens and it has a 10 year warranty. When you order a new Haze you have a menu option of 20% discounted accessories, so this helps out a bunch. What did it cost me for all of these, my total came to $308.13. That included tax and shipping. Hope this helps you out some. Cheers!!