Hi Mario,
I`ll pass on giving any "buying advise" , but I will say that there "real" (non synth) instruments are under rated.
I realy think it would be a fine piano.
Yamaha makes soooo many things that I don`t think a lot of people take there intrsuments (acoustic) seriously, but they should. Before a bought my Guild D55 (guitar) I tried a concert size Yamaha guitar and I liked it very much but being a display model anyone and everyone "played" it and it showed. It didn`t have the "action" of a D55 but very close and a nice instrument.
About the piano, all I know is that they must be tuned about once a year and where it has a one year warranty I`ed try for new strings and a "retune" after 6 to8 months.
That`s about all I know about piano`s.
I hope this info helps and I wish you all the best and many happy hours playing
Keep us informed, good luck !!
jedi