Replacing a Marantz 7025 with a Pioneer M-90/91 in 2018?


I currently own a Marantz 7025, I am using a Pioneer U-05 as a pre-amp and dac currently. I was thinking of selling the Marantz to pick up a M-90 or M-91 for an amp due to its 200w into 8 ohm vs the 7025 is 140w, for the retro nostalga and to have a Pioneer setup. My question is it sonically inferior?

My only option for big power seems to be going mono block or go class D amps. But they will easily cost double what a M-90/M-91 will cost.
tetanus
I am running some Salk Silk Monitors. Do not have room measurements on hand. Speakers are 3 feet apart currently, 1 ft away from the wall. I am sitting 4 feet from the speakers.

I am planning on spreading the speakers apart, when I switch to another room. 
What speakers u running ?
what size room?
how far apart speakers ?
how far out from front wall?
how far are your ears to front of each speaker?
best
JohnnyR