Much appreciate the advice, Paul, and from what I have learned from countless of posts, reviews and my own experiences, I would have to agree. Would like to own a 861 v4 (or higher) with some newer than legacy MConfig software as well as some of the more recommended cards for 24/96 room correction ability. IIRC, there are some other enhancements as well that going with a G68J/v4+ would bring as well. Right now, the sound is very good, so I could only imagine what the possibilities would be as I further update and upgrade the electronics.

I would have to admit when having the 861 even with that so very old almost original form, it sounded so very smooth and dynamic, so I am hoping by going with a slightly more modern setup with the G68, I won't lose too much of that sonic character. Looking forward to what room correction can do as well as the upsampling (?)

Just got a second HD621too! So going to integrate this as well but probably will get the speakers all dialed up first as it has been a real chore and challenge getting the speakers to get audio to them from the processor. Was told to have the speakers off *then* turn on the preamp, then each speaker starting with the Master. NO joy until I reverse the Comms cable from input to output even though it seems backwards, it worked - but! when having the speakers on before turning on the G or 861. I was just about to put my Proceed AMPs back in lol..

So, yes, having the HD621, I want to take advantage of my AppleTv 4K (audio only) and Sony 4K BD. Hopeing the sound (PMC?) will be a bit better than high bit rate dts or DD.

Thanks again for the advice!