iOS is Apple's poorest product anyway, I don't get why the public is so obsessed with it when OS X has been the company's best product and the most balanced OS on the market.
When I was using my HTC Desire Z, I used the physical keyboard. I got tired of having to reselect the word that I actually typed because auto-correct chose something else.
On my SGS3, I use Thumb Keyboard. I turned of auto-correct, auto-spacing and auto anything on this as well. I want my phone to register what I type and not what it thinks I may want to type. I also hate auto-spacing. I want to specifically enter the spaces myself. I don't even use the predicted words because the predicted words take up screen space. On my old phone, this not an issue because I have a physical keyboard. On my SGS3, I have to use a screen keyboard which takes up screen space. Adding an extra line for predicted words take up even more screen space. My keyboard already takes up 2/3s or more of my screen when I'm typing. I like to see the stuff I already typed and other stuff around it as I type.
I am using the stock Samsung keyboard on my S3. I find it pretty accurate in word prediction and auto-correct. And it only takes up 40% of the screen not 2/3. I also like it has the most used punctuations at the top strip for easy selection following a word.