PocketMatrix

I prefer Transcriber for most text entry and voted for it, but it doesn't work too well when entering mixed numbers and letters like passwords.

I also like the notepad in Pocket Word and Notes. It works great when you need to take alot of notes quickly, like in a meeting. If I want, I can recognize the words and make corrections to have an electronic record.

Finally, I know you didn't want to hear about add-ons, but I use SPB's full screen keyboard when I'm writing or editing reports or writing long e-mails. It's not as fast as an external keyboard, but I don't have to carry anything extra and I don't need a table or flight tray to use it.