To cancel an autocorrection (highlighted) tap the word you are typing in the text box to highlight it. Then you get the option to add it to your custom dictionary. This is especially useful if it's something you type frequently, like a less common name (like Jayden, my youngest daughter) because if you add it it will come up as one of the first few predictions when you hit the first letter of the word in question. And if it's an acronym, like IMHO, it will show up with the proper capitalization. Very handy for grammar nazis such as myself. If you don't use the word frequently enough to add it, or the autocorrection has already occurred, simply highlight the corrected word and the first suggestion will be what you originally typed. It took me a while to figure this out, and was frustrating to be sure until I did. However, concerning the iPhone keyboard, when I was still using a dumbphone I wanted a 4s like it was the end of the world. That is, until I tried typing on one. It was a colossal train wreck. On my HD7, as well as every smaller WP I've tried, I can let my thumbs fly confidently. You are probably just accustomed to the iPhone, and it may take a couple days to adjust. I say give it a chance. Also, if you have a device that doesn't have the 8107 update, it worth forcing, (see the wpcentral tutorial) as it dramatically increases the keyboard accuracy. Like, night and day.