I checked out a used Petrof P125 upright piano at a store for one of my piano students today. Overall, I liked the piano, but I had a few reservations about it.
1. First were some cosmetic things that may not just be cosmetic. I was told the piano came from the owner's basement. The veneer on the one of the piano legs was cracked (looked like a repair to the leg had been done), and the veneer on the bit of wood that goes from the bottom of the leg to the body of the piano was warped and coming up. Also, the metal hinges on the fallboard and keyboard lid locking mechanism were showing some corrosion and discoloration of the metal. I checked the strings inside the piano, and they seemed to be free of this same issue - the copper strings were still bright. The wire strings may have been blackened in places, though it was hard to see without a flashlight. I also checked below, inside the piano. The wood inside looked clean and didn't show signs of water damage.
2. The touch was regular and even (fast passages came out cleanly, and trills could be reliably executed), but it felt to me to be on the light side and there was a "clunky", or even shallow feeling that I don't know how to describe. I thought maybe the key bushings might have been a little worn, but the side-to-side play on each key wasn't that much more than on the new pianos.
3. Timbre - my students really like the sound of the Estonia I have, which is why my piano tech recommended to take a look at Petrofs. They tried out the piano and liked the sound. I like the sound too, with one exception. Right below the C below Middle C, the timbre drastically changes to be more muted, and the C and above is much brighter. The C and C# there are the start of the copper strings, these sound more like the rest of the piano. Below that C is where the strings go onto the other (what is it called - the bass strings angle top left to bottom right, and the treble strings angle from bottom left to top right....).
So to those more experienced in piano mechanics than I am, any comments on my observations?