This is an interesting one.
I am in Cologne, Germany, for our Christmas vacation, and somehow got a suite that actually has a grand piano in the living room. I did not bring my printed music, but I had it on my laptop, so I was able to at first practice from memory and when I got stuck look up a passage or two on the laptop.
I had never played a Yamaha G1 before. This one was tuned, but no serious maintenance seemed to have been done of it. Here is what I found and felt:
Surprise: The lowest of the base on this 5'3" baby grand had a gowling tone. It was able to carry the most important base notes of Chopin's second ballade with full authority.
The middle of the base started getting thumpy. This is what I suspected a very small grand to sound throughout. What blew me away is that the bottom fared so well.
The treble carried the obvious benefits of duplexing. I was able to make it sing.
The biggest drawback is a very stiff action, which I suspect is due to the lack of maintenance (may need new bushing & pins in the hammer shanks, or who knows what else)
I am a piano snob, or at least for a long time considered myself to be one. I was surprised at the hidden potential in this small grand. I suspect about US$ 1000 or so would get the action going again. Though I am no expert at scale design, I suspect with the resonance of the bottom bass, the middle base's thumpyness could be fixed by some voicing. I am not surprised to see that as a mass-produced non-premium piano, in good shape, this discontinued model still pulls about US$ 8,000 in the market.