It is a very nice way to work on JPEG's. The sliders allow you to make very small, incremental changes, especially the parametric curves window.
Working with JPEG's where information has already been discarded, the changes are not as smooth as working with a RAW file...contrast seems to build up faster so you can't make a lot of big changes, but the camera's processing system gets a lot right up front, so for the most part the need to make large adjustments is not there when it comes to working with JPEG's in ACR. Fortunately, the nature of the adjustment tools makes making small tweeks very easy, yet keeps the original file intact.
Working on the files in Photoshop and keeping adjustment layers requires saving the file as a large PSD or TIFF, so adjusting JPEG's in ACR also can save you lots of disk space if you want to retain adjustments with the ability to go back and tweek them later.
You've got some gorgeous images there, Zig.
Last edited by Greg Chappell; Dec 2, 2009 at 10:03 AM.