I just played on a Steingraeber & Sohne (that's not a Steinway, it's leagues above

), about 6 feet long, and it was simply the most incredible piano I've ever played.
It felt like instead of one cohesive piano, each note was a seperate instrument. It felt like I was conducting an orchestra rather than playing on a piano. This allowed for the most stunning counterpoint and voicing I've ever encountered on any piano.
The dynamic range is incredible, but pounding the hell out of the thing still produces a beautiful, singing tone. You can play pianissimo with such splended magnificence...
And most incredibly, it was absolutely effortless. I've never felt such control over the sound I produced. Some pianos require adjusting to, but the only adjusting needed with this was not to get hung up on every single note because they are all so beautiful.
Not only is this piano good for solo practice, but it's incredible for chamber music as well. I don't understand it, but even when you play as loud as you can, you'd still hear a pindrop from across the room. Rather than drowning everything with it's power, it seems to flood and flow and enrich all the other musical instruments near it.
The one catch is that it cost about 75,000 USD. But if I could buy this piano one day, I'd just retire right then and there.