I've been using a Yamaha P7000s (750W x 2 @ 8 Ω; 950W x 2@ 4 Ω) for 5 years. Yamaha has a newer line: PX series models are driven by a newly developed Class-D amplifier engine with a custom LSI.
The PS series touted Yamaha's own digital EEEngine:
EEEngine delivers incredible power while preserving sound quality
As a power amplifier's output increases, its driving mechanism becomes more significant. Yamaha's exclusive EEEngine amplifier driving technology supplies the voltage level necessary for the level of input signal through switching circuit and smoothing circuit, producing a highly effective driving mechanism. This is a revolutionary power amplifier driving technology that offers the function of a Class AB amplifier and the efficiency of a Class D amplifier. EEEngine gives you fantastic power, highly efficient driving function, and tremendous energy savings, all without sacrificing the sound quality demanded of a professional power amplifier. This technology is included in many of Yamaha's power amplifiers, and proves its utility in all kinds of situations, from sound reinforcement to permanent installation.
I had previously used a QSC GX7 to power the front Polk RTia9s in a 7.0 HT; using a Pioneer SC-07 as a pre (the SC-07 was fine for HT; but => listening fatigue for 2-channel CD, I believe its early ICE amps' 140W was too little for the RTIa9s). They became "musical" with > 700 WPC. The fans on the QSC ran constantly, => low WAF.
I replaced the QSC with the Yamaha P7000S. The fans have never come on. I replaced the SC-07 with a Yamaha RX-A1050 2 years ago. Use a BD-A1040 as a 2-channel source, amp & player in Pure Direct.
Recently upgraded the front 2 speakers to Focal Electra 1038BEs (93dB, 3.3 Ω min.) I've read a lot of Google that the Focals would be revealing of less than acceptable sources/amplificaton. I have no complaints. The Focals are a vast improvement over the RTia9s; the WAF? I didn't think I'd be able to hear the difference, but I can.
I'm using some very cheap RCA>XLR cables. The P7000S was a B-stock from ebay for $600.
Among the latest offerings, I've contemplated the PS Audio Stellar M700 monoblocks, as their form factor & looks are more conventional than the P7000S; and ~ half the power @ 5 X the price.