(donjuan: I don't get it... size for size, how can Petrofs be more expensive than Yamaha's C-series?)
Personal opinion here: As for Renner vs. Yamaha's action -- I don't see Yamaha's as inferior. I played many new Yamaha's and their actions are very good compared to everything else out there. Not all "Renner" branded actions are equal. Renner makes different actions at different quality levels using different spec's from different piano makers at different price points. Yamaha does just find with its own action.
Boston -- sold by Steinway to compete in the mid-price market, but made by Kawai. Get it if you like it, but compare with Kawai's comparable models (i.e., K- and RX-series, similar sizes) first. Size for size, you can usually get Kawais cheaper than you could Bostons.
Essex -- sold by Steinway to compete in the low cost market, but made by Young Chang. Get it if you like it, but compare with similar-sized Young Chang and Pramberger pianos (also made by Young Chang) before you decide.
For up to $10,000 (assuming US Dollar and that you're shopping for a new piano in the US), that's a lot of money for an upright. Go try the Italian Schulz-Pollmann (48" or taller), go try the Yamaha U3 or U5 (52", if you can find it), go try the Kawai K-60 or K-80 (52", if you can find it). Those big Yamaha/Kawai pianos can give you big sound.
For grand piano in the under $12k price range, not many good choices out there. See if you can find the discountinued Weber 5'7" (made by Samick), may be RX-1 or the G(something) series from Kawai. Not even sure if you an get a C1, may be Yamaha's G(something) series might work in that price range. But you should be able to get a pretty good used Japanese piano (10+ years old, perhaps 6 to 6-1/2 foot grand). Small (under 6-foot) Eastern European pianos like Petrofs are also possibilities.
For under $10k, you can definitely get new Chinese-made grand pianos, possibly around 6' in size, plus/minus a few inches. The ones made by DongBei, but branded "Nordiska" or "Hallet Davis" are the more reputable ones I hear people (piano technicians) talk about as being "a cut above the rest of Chiinese pianos." What I've heard is that they need some rather thorough voicing/regulation work after purchase, but should work well after that. (I've never played them myself, just relaying what I've read/heard.)
Play lots of different pianos before you decide. Words cannot sufficiently describe sound and touch. You won't know what you like until you try lots of different brands/models.
Play lots of different pianos before you decide.Good luck!
