I tryed and I really like it. The best thing is that dual monitors are supported, so I can drag the picture to one monitor and work with the settings on the other.
There are some interface changes that I couldn't get used to yet (the settings open on the steps window and the advanced options are all embedded there). I noticed that now I can turn off an intermediary step without having to turn off all the following steps. And there's support for CA removal from non-NEF files!
Also, the selection control point is really good. I had no use for it yet, but it works very well, just like the color control points.
Overall, I think it's a little slower than 1.3. And yes, it still takes a long time to save the NEFs!