IMO, if you can find an MCP-18, there is no alternative at the price. Especially the price it was last sold for, i.e. USD 599 or, well, if you just need an 8-channel analog pre-amp instead of stereo. (May I ask why?) My favorite line stage is a resistive passive. Coupled to a high input impedance amp and low output impedance sources it is utterly transparent. The MCP-18 reminds me of it. It does not add any coloration of its own. It's like it's not there. For a while I ran Genelec M030s off the MCP. Great combo. (Now I'm back to passive speakers powered by a MCA-18. 50% joy, 50% disappointment in that amp. Different story.)
I never needed anywhere close to unity gain for music at home. Most of my sources have low output impedance and can deliver current, and output 1 to 2 Vrms. My amps have 26 or 32dB gain structure. Speakers are 86 to 92 dB/2.83V/m efficient. Curious what your specs are.
What I like about the Parasound, other than its gorgeous looks, are the x-over and HT bypass features. I have not heard a P7.
BTW, the MCP-18 accepts 50/60Hz, all voltages, auto-sensing. So does the P7 AFAIK. A serious contender, but for a lot more money.