I read through as much of this thread as I could stand, and I want to post my experience here. Please note: I can't tell you how many hours it's been since I unplugged, I have better things to do with my life. The DINC2 is a tool, and it's a wonderful tool, by far the best smartphone I've ever had - EXCEPT for the battery life, which is affected by the fact that I live in an area with a crappy Verizon signal.
I've had the phone since May, about 3 months. It was an upgrade from a Samsung Saga running Windows Mobile 6.1. On the Samsung, I used to be able to go 3-4 days between charges, and be confident that when I wanted to use the phone, it would work; my usage was light because WinMobile 6.x is a relatively clumsy interface. I make almost no phone calls and I don't text; I mainly use the phone for internet surfing, and games when I'm waiting for something. My phone usage is up somewhat from the Samsung because the dinc2 is more fun to use. But it's too often the case that when I want to use it, it needs charging.
The most I've been able to get out of the dinc2 battery is a day and a half, which means it's always dying at some really inconvenient time. I did the "full charge" routine to condition the battery for probably a week. As far as I can tell it had no effect. I finally gave up and just plug the damn thing in every night. I've never had to do that with another phone. The only alternative to this is to put the phone in Airplane Mode all the time, and turn Airplane Mode off when I want to use the network; it's the network that eats the battery as far as I can tell. I run brightness at the lowest level (unless I'm outdoors), I turn the display off manually when I'm done using it. I don't run "bloatware" - I run nothing that I don't actually use.
I would like to know if the extended battery is worth the money. I'm willing to pay for things that will make my life easier; from what I've read in this thread, the battery life I've seen on this phone is ABSOLUTELY NORMAL given I live in a low signal area.