If I remember correctly the PR804 is the same size as a piano and that is exactly what it is - basically a piano with the addition of styles and patterns.
When it first came out a friend of a friend asked me to go to his house to help him become familiar with all the lovely features it has. Whilst it is a great instrument with 88 keys (ideal for piano players), to me it was a larger version of the KN7000, so if you don't intend to play it as a piano utilising the extra keys, I see no point in you buying it, unless you have a special place in your sitting room because of course, pianos and organs do usually take pride of place in a sitting room don't they? Be aware though, it doesn't have the lovely shiny finish to the cabinet as my PR900 piano does, nevertheless, it is still a fine looking instrument.
Hope this helps.
Audrey
[This message has been edited by Audrey Turner (edited 10-13-2010).]