I used NX2 a while back. When Windows 7 came out and NX2 was being ported to 64 bit, I gave up on it due to the hangups and frequent crashes. This was about the time LR 3 was introduced. I have used LR in my workflow since. Several other members covered some of LR highlights already, I will not repeat them.
JPG or RAW???
Everyone's mileage may vary. I shoot raw the vast majority of the time, especially when it is an image I really care about. The raw benefits have also been covered in this thread. Again, no need to repeat. My workflow begins with a quick review of images in ViewNX2 where I delete images that warrant the bit bucket. If snapshots are all that are needed from a particular batch, I use ViewNX2 to capture the camera settings and do the batch conversion. If they need to be saved in my LR catalog I import and am done with post.
The images I really care about are handled differently. After culling in ViewNX2, I import into LR. I rarely will use auto tone cause it tends to mangle things often. Where possible, I sync settings for the imported images. Now the real work begins. I edit images in LR, using all the basic settings, brushes, HSL, etc. If I get the result I want, I'm done. If the image is not what I want, I may revert it, or take the LR edits into PS CS6 where I can use the CS6 tools and the NIK suite. The more I learn about the NIK suite and CS6, the more I am using it for the images I want to place on my website. The result of the CS6/NIK processing is brought back into LR where it is stacked with the original raw. I use LR for all exports for web and also print directly to my home printer from LR.
I know I could most of this post processing workflow with a jpg as a head start, but landscapes with a shadows, highlights and fine details, IMO, come out better when starting with raw and only generating a jpg at the end. I try to avoid HDR if possible since I have difficulty getting realistic results. Take this as my inability to consistently do a good job with HDR editing, not as a slam against HDR. A few of my favorite sunsets/sunrises on my site are HDR.
I appreciate there are many post processing editing options on the market which can do a great job and would never think there is one best application set or one best workflow.