I've been an iPhone user since day 1.. I've never had any problems with the iPhone keyboard.. Idk what's going on with your phone op.. I'm even typing thi message with one hand driving down the street without looking.. Im relying on autocorrect..
For the person coming from a blackberry. Turn autocorrect back on. I can't imagine typing on any screen, even if isnt an iPhone without any type of autocorrect.. Autocorrect is your best friend.. The key is to trust it.. And if it wants to replace a word you typed with another word that you don't want, you can always use the blue x..
And idk y, just my 2 cents.. I type faster on my iPhone in portrait.. I remember when we didn't have the option to use horizontal to respond to text messages etc.. I can type left handed, right handed.. 2 handed.. And I type just as fast 2 handed that I do with either hand.. I'm sorry, but I think I'm the sickest iPhone typer ever lol. I think ima make a video now.. B
But yea. The key is to trust the keyboard