I've tried Swype. I don't get it. I mean, I get how it works, I don't get why people like it. I want to type, I don't auto-completion or guessing. I don't want to switch context from typing to reading words from a list and then selecting them. It is slow and inefficient.
Plus, honestly, I think that Swype is particularly bad for me as a lefty. I don't think the tracking algorithm is righty-only, though it may be, I suspect that the greater issue is that in English, we read from left-right. Since a lefty's thumb covers the left-sided keys as they Swype, you really need to read the keyboard from right-left to operate as efficiently as a right-handed user. This results in a much steeper learning curve.
Finally, I work with Linux/Unix systems and the primary purposes of my Android device are to login to machines via SSH and to send emails. Both frequently contain Unix commands, Python source code, HTML, and other forms of non-English input that very often includes special characters. Most software keyboards fail miserably with these, and for this, Swype is particularly bad. Still, the size and layout of the default Galaxy Tab keyboard is surprisingly good, good enough that if not for being stuck on Android 2.2, I'd buy it in a heartbeat.