Yamaha U1 vs YM10

[mikaili]

Hi, I'm about to buy a used YM10 Yamaha Piano,
I've been searching the net for many days for a thorough comparison between U1 and YM10 Pianos but I could not find any.

Many sites claim that they are almost the same but some say not.
I could not even find any thing about YM10 specs on Yamaha site.

Does any body know precise specs of YM10 in comparison to U1?

I'll be really thankful if some one helps me.

[indianajo]

I've heard several Yamaha vertical pianos. I played one with the floppy disk playback system.  I don't like the sound of any of them.
As a result I never inquired what model they were.  The one my church bought sounds like ****.  I won't even sing with it.  The music committee and deacons probably all blew out their ears with weapons, motorcycles, and gasoline power tools.  So they have no idea what they are missing.  I was tested okay up to 14 khz in 2008, and still wear earplugs in the above situations, also rock concerts.
The predecessor 1982 Everett studio model, that I auditioned in comparison to a Steinway 44" and a Sohmer 39", came out third.  This is the Michigan factory Yamaha bought and then shut down.  
The Yamaha 9' grands sound okay IMHO.  But the Yamaha baby grand I played was mediocre sounding.    
Specs mean nothing on a piano.  The function of the left and middle pedals are the only significant specs that are even worth looking at.  The number of dampers is interesting, those models missing more than an octave and fifth are usually also short scale design.  The top octave sounds stupid on short scale pianos, usually.  Speed of repetition of a single note is important, but nobody I know of quotes a spec.  Yamahas are usually fast enough. 
Enjoy your shopping experience.