I came so close to switching to Things today. I'd been getting a bit disillusioned with OF as I felt I was getting bogged down in detail and had started dreading using it - especially my weekly reviews.
The geek in me also likes something new to play with, so I downloaded the trial of Things 2 and dabbled with it for a bit. I felt quite excited by the possibilities, however, it was missing a few things that I don't know if I could have lived without (in particular folders and nested action groups).
I went back into OF to copy some tasks across and see if I could make it work for me in Things. While I was there it suddenly hit me that the problem wasn't with OF but with my organisation. I'd been lazy and let OF become cluttered with tasks which would never be completed, lists/projects that would never be used again etc etc. I'd also been living with the same folder structure that I'd been using for years, and it wasn't quite so representative of what I'm working on today. So I've just finished performing a complete spring clean of OF and re-organised most of my tasks into new folders, lists and projects. I've set up some new perspectives and consolidated most of my tasks into a more streamlined and relevant structure.
Having now cleared out OF I feel so much better about it and have some new ideas of how I'd like to use it. I'm looking forward to OF2, whenever it might come out, but for now I'm enjoying my existing OF setup all over again!