Actually I didn't want to try it out, even though I purchased a license with the recent MacHeist bundle.
As I started to think about the missing features in Things (which is going to be great, I believe - and far more flexible to suit your needs than iGTD, which I left for good) I just wanted to see how TaskPaper stacks up against it.
And ... it's great. I can literally develop my own sorting and prioritization system with the task, while the interface is just great: KISS at its best.
I'll stick with it for now and keep an eye on Things.