So you've decided you want an electric baby
Before I get into specific recommendations, I want to cover the factors that
should go into your decision so you can get the
best possible digital piano.
Size / Portability
When it comes to size, you have a large range of pianos to pick from. For
example, Yamaha makes "grand" electric pianos that are just slightly larger than
a keyboard. They're designed to simulate the sound of a grand, but most find
them to be lacking when compared to the real mccoy.
However, the trade off you make there is that they're highly portable. If you're
on the road performing, it's a lot easier to take a small electric piano in and
out of the concert venue than it is to transport a full size grand (even if it
is electric) all the time.
Next up you have to decide what kind of sound you're after. If you want
something that will sound exactly like a grand, then you're going to want one of
the high end offers from companies like Kurzweil and Kawai. They look just like
real grands and can simulate real pianos strings and grand piano acoustics well
enough that even a trained ear will have a tough time telling the difference.
(Note: If a symphony orchestra needs to use an electric piano, it's probably a
Kurzweil - one of their digital pianos was also featured in the 2010 Superbowl
halftime show performed by The Who.)
The last factor here is going to be price. The smaller digital pianos are going
to be cheaper and easier to move around. The larger electric grands are going to
give you superior sound but they're also going to run you several thousand
dollars. In fact, some of them rival the prices of their real "string and
hammer" counterparts... but then again in many ways you get what you pay for.