Liz:

My set up touches on some of the things you're inquiring about: I'm using the 970 (which is basically the 1070 sans power) with 2 outboard amps: a McCormack for my mains and an Emotiva for my surrounds.

Unfortunately, I don't have the benefit of a direct comparison with the amp section of the 1070 versus those amps.
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Outlaw 970
McCormack DNA-125 (mains), Emotiva LPA-1 (surrounds)
Quad 11L (F&C) Wharfedale (R) LFM1 (Sub) w/ SMS-1
Squeezebox -> Behringer SRC2496 -> Musiland MD10 DAC
Sota Sapphire; Marantz 10B;
Video: Hitachi 42HDS52A; Oppo 971H
System Pics