I am looking for a new controller for Sonar and can pick up a mint Edirol PCR800 for $100.  Will this still work well with Sonar?  
Thanks,
Alan

You do understand that MIDI is midi and that a keyboard from 1980's if it has midi ports would still interface with any DAW. Midi has not changed. 
  But if there is no midi ports and it uses USB for midi connectivity then there needs to be special drivers. Drivers  that work with your OS version.  
 So the question is easily answered by a quick trip to Roland's support page where there are divers for windows Xp, Vista, 7, 8 and 8.1.  So yes it will work with any version of any DAW you have. 

I can confirm that the PCR-300 to 800 will work with Windows 8.1 and SONAR Platinum.
 
Kind regards,
 
tecknot

I have the PCR800, Win8.1 and Sonar platinum. It's a nice keyboard (for my needs at least) and I haven't noticed any difference compared to X3 so far.