I agree that Michael seems to be getting outstanding results from his A900 and Lightroom at low ISO, so the differences I'm seeing between Lightroom and C1 on screen at low ISO using A900 files must be of the pixel peeper ilk. However, as the ISO raises, C1 drastically starts separating itself. For me, local image adjustments is the only real advantage to Lightroom, but I often have to use PS anyway, so it isn't a huge issue. I'm keeping my eye on Bibble 5, as that may end up being the best of both worlds for how I work.
Either way, whether using Lightroom or C1, there are some immediate adjustments to be made when converting A900 files. Both programs benefit from using a linear tone curve, rather than the default contrast of "film" curve. Brightness, especially in the case of Lightroom, also should be lowered upon import. With C1, I find myself lowering the brightness and darkening the midtones in levels frequently. I've been hearing the term "expose for your RAW converter" thrown around a bit, and I'm starting to catch on. For me, I start by getting jpeg settings in the camera that give me the most "RAW-accurate" histogram on the camera's LCD, and I use uniWB frequently to really make sure that I'm getting a proper exposure. UniWB has gone a long way in showing me that I've been underexposing my Sony cameras more than I realized. Loading uniWB into the camera, and using jpeg settings like the following gives a pretty accurate RAW exposure simulation:
Neutral creative style