The Two-Cell Bolder LC90 goes mostly unchanged from the original LC90, but most of the changes that were made I'm not in love with.
The main selling point of the two-cell is for longer battery life. I have not tested it on this one, but on the original I was getting about 6 hours on high, so I assume this will get you about 12.
Anker has also relocated the micro USB port for charging. It is now next to the button. This change may seem exciting at first, but there is a sacrifice. I'll get to that in a minute.
The Light Itself
Brightness is unchanged from previous model. I'm still very satisfied. The LC90 models also continue to be the only flashlights from Anker that support zoom/flood functionality. Originally, your instinct may be able to turn the head, but you do not. Rather you push/pull.
The sacrifice comes with turning the flashlight on and off and switching between modes. My biggest complaint is that now that the micro USB port is on the front, the button is so small compared to the original. This makes it much more finicky. It's not horrible, just quite a bit worse. With the increased battery life, there is less a need to charge it as often, so in my opinion this tradeoff just isn't worth it. Also you still can't use it when it's plugged in, anyways.
The Obvious Tradeoff
Of course, this flashlight is also much larger and heavier (see pictures for reference and Amazon links for specifications). Again, in my opinion, it's not worth the tradeoff for most situations. I suppose this could be beneficial for an extended power outage when you need light from sunset to sunrise and then can recharge during the day, so if that is your only intended use for this, the two-cell may just be the way to go.
Overall, while this is still a well-performing flashlight, for most people I think the original LC90 is a better choice. Oh, and it's $10 less expensive.