The Yamaha weighted keyboards are a great buy in my opinion. I just went through the same process, wanting to learn piano but live in an apartment so an acoustic piano was not an option.
I am so glad I went this route. I have played a few pianos at friends houses, and for the most part they are pieces of #$%^. I can't stand out of tune, and I can't stand the rattles and buzzes. I can't stand broken keys. It would take a considerable amount of time and effort to buy and maintain an acoustic piano, while the keyboard will stay in tune forever, and the action probably doesn't degrade much either. At about a grand or so, if I wear it out I can just get another one.
Judging by the average YouTube performance, the sound quality is way better through headphones and recorded than all but the most professional instruments (recorded well in a good room). I won't say that a great piano isn't a nice thing to have, but not many of us can justify 30 grand or more plus regular maintainence. It will be awhile before I ever need to perform, the speakers on the Yamaha are really quite awefull. I need to experiment with sound reinforcement, I have a small Roland amp, but it didn't sound good either.