For those that cant decide which piano to purchase, here is a wonderful high quality video, that Stefan at Vienna did awhile back. He plays 3 pieces, on all 3 pianos, so you can make a comparison between the 3 pianos. The difference is very subtle, and you'll need some good headphones / studio monitors to hear the difference, but in general, the Steinway presents a more muted and blended sound, perfect for orchestral works, the Yamaha is slightly brighter, while the Bosendorfer has an emphasis on the bass (the Yamaha and Bosendorfer are great for solo works or when the piano needs to cut through the orchestra, rather than blend with the orchestra).
My hope is that Vienna will re-record the Bosendorfer, in the same manner they recently did the Yamaha and Steinway pianos, because the demos of the Vienna instruments version they currently sell, sounds rather bland, flat, and muted to me.
Also, for the love of God, please put some demos of the Steinway and Yamaha from the player and close position (and include this in the description of the piece) because I love how these pianos sound in this video, but all of the demos seem to include more of the room accoustics than I want. As a pianist, I want to hear these up close and personal, much like how they sound in this video.