It's heavy, the battery life sucks, and the interface isn't designed for tablets, but I can get more work done with it than the other 2 combined. Even discounting the keyboard, it's still more useful.
I can run all the same apps on my Win7 laptop and on my Duo. I can start a project on one, email it to myself, and continue it on the other. I also know that no matter what i download I'll be able to open it. Neither mobile OS has any real support for Office formats, not even basics like RTF, ODT, or others.
The deciding factor was when i tried to download ebooks from Fifth Imperium, a free ebook website. I couldn't download the files at all on Android, and on the iPad I had trouble getting the Kindle app to open the compatible files. With the Duo I simply clicked "open with K4PC", and it worked.
The same goes for all my other data. Just a few minutes ago I copied 70GB of work files onto the Duo. I didn't need more than about 100MB, but copying the files over was so easy that I went ahead and grabbed them all. I know that I will be able to open whatever I happen to need, so why not?
Frankly, iOS and Android have crippled file systems, and it gets in the way. The truly bizarre part is that they're both based on *nix, so there's really no reason for them to be crippled like this.