SFZ has had the best reviews so far. For some reason, most of the discussions have been on JK Forum. Apparently, the fit is great and they are very well planned.
The Element doors are great for those that want tube doors and skins. But they are kind of an eyesore from the interior with skins on. I have also read many review about their seal and keeping the elements out.
I have been waiting to see the SFZ uppers, but they are behind on product development. The great thing I have heard about these it that they will have a sliding window.
The rugged ridge half doors are also pretty good from what I hear.
All that being said, I am saving for OEM half doors...simply because SFZ decided to go with a textured finish and you can't paint them to match the body.