I'm getting used to it pretty quickly. Being a touch typer it's hard for me to think where the letters are on the keyboard when my finger is swyping around. Sometimes I end up with extra words but it's surprisingly good at figuring out what I was trying to do. One tip that has helped my speed is to just swype out what I want to say and ignore the pop up box. Then go back and double tap on the words that aren't right and change them.
The other thing I really like is the two kinds of number keypads. The square one makes it much easier to enter a bunch of numbers than the others I've tried.
One reason this is probably in a long beta is that they're still tweaking it and you don't get as many complaints if people didn't have to pay for it. Plus, we get hooked on it and then when they do want to charge, we're much more pliable. I can imagine that if someone thinks they have to like it in the first day or ask for a refund, it's better to build up a bunch of advocates who already like it.