From what I know of digital and acoustic pianos, acoustic pianos will general have a much fuller/richer tone & sound. Digital pianos seem to miss the mark in one way or another. I don't know if it’s because of the way the tone is generated, or because of the action of digital pianos or whatever else. That being said, digitals have some nice advantages, they are generally portable, do not require microphones, do not require tuning, you can do countless takes without disturbing neighbors and family.
I once moved into a small apartment and I had to sell my piano because there was simply no realistic way to move it into the apartment!
I also tend to think that a skilled piano player can make a toy instrument sound good. I tend to think that as long as the instrument is in tune, clear, without too much reverb or noise for example, the performance is more important then the instrument (not that you can tell this from my own recordings...) Anyway, this is all just my own opinion and feelings about this probably vary.
I can't seem to produce any good quality acoustic or digital recordings, and I need to decide on whether to invest my money and energy in acoustic or digital recordings. I have a really good German grand piano and a Clavinova CLP. The grand piano is fine, but the single microphone I've used is not great, so it picks up all sorts of unwanted noises but can't cope very well with fortes, and the other problem is that the room is fairly small so it also sounds dry. The Clavinova is perfect in that you get the pure sound, but is so absolutely dry that you get no ambience sound, and besides, it does sound very much like a keyboard. I tried downloading some software to give some "ambience" to the MP3 but I efforts yielded nothing but garbage.
From what I've read so far, I gather it's really difficult to record a grand piano. I don't mind investing in equipment, but I really don't want complications. The other option is to get a really good digital piano but I'm disappointed with most of them - even with the Roland HP 207. I tried the Roland V Stage Piano in a shop yesterday and it sounded great compared with all the others, and it was really easy to change the ambience and all the settings, but it's also rather at over £4,000.
I would like to hear what you would choose if you were in this position. Ease of use is my main requirement, followed by quality and cost.