I just downloaded the Adobe Lightroom 4.0 Beta. I think it's much improved over the previous version. I've been using Pixmantec's RawShooter. After Adobe bought RawShooter I really wanted to see some of the tools from that software incorporated into Lightroom. Then I bought the Canon Digital Rebel XTi and couldn't use RawShooter for RAW conversions anymore and really really wanted to have RawShooter tools included in Lightroom. I haven't shot a Rebel XTi RAW file to test with Lightroom yet. But the Develop stage of the software has RawShooter's excellent crop tool, Fill Light, and Vibrance controls. It doesn't appear to have RawShooter's separate highlight and shadow contrast controls, which I really like. But I'll have to experiment some more. They may just have different names now. In any case I'm pretty pleased with the new version. Lightroom is starting to look good to me.
Who else here has been experimenting with Lightroom? What do you think so far? Can you compare it to anything else? I'm curious how it compares to Apple Aperture and Phase One's Capture One.