man, I love Swiftkey, and Swiftkey 3 more than past versions. I can type fast as hell and it gets it right 99% of the time.
One thing that might help is to set the spacebar to "finish current word" rather than "always insert prediction". I find that this setting alone makes a huge difference. (** Which someone already mentioned**)
Also set it to "Rapid", rather than "Precise".
An issue I had with previous versions is that it suuuuuuuuuuucked to type in my email address which has periods before the @... I'd have to hit the period, select the leftmost prediction, backspace to delete the space it places after punctuation, etc. With Swiftkey 3 that behavior is gone and I can just blast through the thing.