Are there any differences to the old non 3D version and the new obviously other than the 3D board allowing pass through. It would seem that you can pick up a used old AVR600 for around £1100 and the board costs around £500 to update to 3D which comes in at significantly cheaper than the £4400 Arcam want fot a new 600 with it already fitted. I assume all the pops and bangs have now been addressed via firmware updates by now?