I just installed Lightrrom 4, and figured I’d give it a quick test. I found a photo that I took last year that was quite underexposed, to see what I can do with it. Right off the bat, when I made the process update to the LR4 “2012 process”, the photo was instantly much better. The ability to use the adjustment brush to selectively add noise reduction (to her skin tones only), and highlight and shadow adjustments (to the brick), in my opinion, make the photo much more pleasing. There aren’t many functional differences between LR3 and LR4, but my first impressions is that the technical aspects (the “algorithms”) used by LR4 is going to make my photos better and improve my workflow.