Is Capture NX any good for JPEG shooters? Although it is mainly a RAW converter for Nikon NEF files, it is also a very useful tool for for JPEG shooters.

For the most part, you get the same powerful editing capabilities as for NEF raw files. Plus, you can save all your edits at the end in NEF format non-destructively! You can go back to your original JPEG photo embedded in the NEF file without image quality degradation. You can also create different versions of the same JPEG photo and save them all in a single NEF file. Of course, you can export JPEG file again.