Just took ownership of an SC-57 (new). Found a great deal from Magnolia.
came from the legendary Onkyo 805....then to a pioneer 1121k.....but wanted more inputs like multichannel analog....& maybe a bit more slam. So bought the Onkyo 3009.
Definitely more sheer power & oomph. It moved the furniture & the LFE from dual SVS subs was stronger. But the onkyo sounded dry to me. I missed the more open & airy sound from the 1121. The pioneer had that top end sparkle if you will without sounding fatiguing.
So that brings me to the SC series. Wasn't sure about the D3 amps. Did some research & got good feedback from Steve (ss9001). Very helpful. Couldn't really afford the new 68 model as I also wanted the new Oppo 103/105
Enter the 57. Quick observations are I love it. Equals the slam & immediacy the onkyo 3009 had but with a more airy & open soundstage. My main LCRs are Klipsch Heresey III'S. I realize the Klipsch Heritage lineup kind of has a love/hate thing with people. I love them & probably won't ever be without horn loaded speakers.
The SC-57 sounds smooth, detailed, & full of muscle. These speakers are very efficient & probably overkill to use that much power. But it sounds fantastic.
The remote is a weak point. Dang small buttons that are hard to see. Especially in a darkened front projector theater room.
I'll have more time to really dial in & tweak but just for a quick setup weekend it was marvelous.