Even I haven't heard the Simaudio, I still would go for the Playback Designs, Mr.Kosch has done the magic and believed they have the top notch technology, BTW, I'm a happy owner of a MPS3.
Playback Designs MPD3 or Simaudio 650d
Come on guys chime in on this one. I've my homehad the pleasure of the mpd3 in my home for a three day audition and have been blown away. I have not heard the 650d bu t its on my radar even though its 1500 more. So before I pull the trigger I'd like to complete my due diligence and look to all of you for some welcomed feedback.