Definitely an all around improvement. More musical, better bass control but it did loose some bass punch.
Then I switched XLR interconnects to Mogami's made by Jerry of 10 Audio. This was a big improvement. Detail, clarity and bass improved. I highly recommend them for $109 for 1 meter pair.
To me the amp and the Mogami XLR's ended my search for improvement. My system sounds great to me.
FYI
I was using XLR's by Raven Audio. Jerry cables are listed here on Audiogon.
My system:
NAD C 658 Preamp with HDMI module.
Parasound Halo JC5.
Audioquest NRG-Z2 Ac power cords for pre and amp.
Velodyne HGS 10 sub.
LG 65 inch TV.
Logitech 665 Remote.
Arcam DVD/CD.
Mogami XLR's By Jerry at 10 Audio.
Audioquest Cinnamon 48 HDMI cables.
Audioquest Greyhound Sub cable.
Mogami speaker wire 2921.
Speakers are Bi-wired.
Sonus Faber Olympica III.