For a change I had some free time today and was able to download the trial version of A2 and hence can now answer my own questions:
1. No, A2 is not a photo editing programme and doesn't have selection tools that allow selective burning and dodging.
2. But it is very good at overall editing and its default setting result in an excellent, subtle, rendition both in colour and B&W. For me that is the starting point because I then proceed to "destroy" this "exquisite" rendition to get the type of expressive prints that I want. However, I believe most people will be quite pleased with the default settings, which really do have excellent sharpening and noise reduction settings.
3. While I feel that the A2 default settings are better than those of LightRoom, the latter, for me at least, is a much more intuitive user interface: I like the contact-sheet type view of LR much better and the way of going from the view to the Develop facility, as well as the way exporting tiff and jpg files are handled is much more intuitive than A2.
4. As I use LR for RAW file viewing management and then do everything in LightZone the intuitiveness of LR is important I'm going to continue to use it rather than switching to A2. But user who want to do the type of editing that LR and A2 are designed for may wish to consider A2 because of it's beautiful rendiition.
—Mitch/Bangkok
http://www.flickr.com/photos/10268776@N00/