Disklavier

I know this is a disklavier forum but maybe someone here knows...

What degree of compatibility is there between Yamaha 'musicsoft' 
titles and Roland KR (intelligent) digitial pianos? I know Roland 
plays smf (standard midi files) but can they play, for e.g., a 
pianosoft solo, xg, or clavisoft title? If so...is playback 
equivalent?

Also, within the Yamaha musicsoft site(www.yamahamusicsoft.com), 
music is categorized based on instrument--clavinova, disklavier, 
etc. Within Clavinova you'll see subcategories such as CueTime, & XG 
Piano and within Disklavier you'll see subcategories such as 
PianoSoft Solo and Virtuoso Performance. The data format for 
PianoSoft titles is 'Yamaha pianosoft' but for Virtuoso the data 
format is 'Midi Song'. What is the difference? Is 'Yamaha pianosoft' 
a proprietary format that ONLY Yamaha instruments will play 
and 'Midi Song' is non-proprietary, i.e., playable on non Yamaha 
instruments? Is Midi Song = SMF?

If there is a one stop resource someone could point me to inorder to 
sort all of this out, I would appreciate it. 

A confused newbie ;)

thanks, jpbtacj