Native english speakers might appreciate a good prediction/correction engine, but for me it's the first thing I disable on a new phone. I type a lot non-words, technical jargon, or transliterated Greek on a keyboard and I just want to have what I typed, not what the phone thinks I did.

With the correction disabled, the N9 has the best keyboard because of it's nice haptics and ability to modify layouts, with BB10 coming second (because of no haptics, no dead keys -you have to longpress to type accented characters- and having always capital labels) and WP third. iPhone is distant 4th (inverted dead key sequence order - you have to type the dead key after the letter, wtf!) and second to last comes symbian which for some weird reason seems like having tiny keys on a 4" display, which is bigger than the N9. Last comes android which on anything smaller than 4" is unusable (upside is that you can choose your own vkb there).