I own the A3 and demoed the entire line at NAMM. I went with the A3 because it seemed like the sweet spot of a balanced signature and value for the dollar. The U6 was excellent but I couldn't justify the price difference at the time. I don't regret going for the A3 at all though. Disclaimer: NAMM is a very loud venue so I probably could have heard a bigger difference in a quiet setting. I'd love to someday have another chance to demo the line in a setting where I could critically listen.
Awesome - that's what I ordered.