As for the power level for the ADA amps.

I have the ADA1000-4 (as in 4 driven channels out). With the LFR1100 you have 4ohm on the front speakers and 8ohm on the rear. So my amp can deliver up to 250w of power to the front, and 125w to the rear drivers.

By comparison, the ADA1500-4 can drive 375w to the front and 325w to the rear. So you are getting 50% more power to the front and a whopping 160% more to the rear.

But, the rear speakers are just tweeters and mids, and I honestly don't see them needing anywhere need that much power as they are smaller drivers that don't need as much current as the larger 6.5" HP woofers. So driving the backs likely gain zero in added performance from a much larger amp.

So now we get to the front. You are going from 250w to 375w ... so a gain of 125w. That is quite a bit more but as Craigsub pointed out, this is a number at the high end of the volume where I believe it takes double the power for each db gain. so you've gained 3db for your more than double price tag.

What is missing inside this is dynamic peek power. Both these amps are plugged into a 15amp wall socket, so there is a limit to the amount of constant power they can pull. An ADA1000 is not limited to 250w, and can provide beyond that for short pulls. not nearly as much as the ADA1500, but what is not answered is would the amp have enough not to clip and if it did, by how much? And at what volume?

Anthem: AVM60, Fosi DAC-Q5
Axiom: ADA1500, LFR1100 Actiive, QS8, EP500, M3, M3comp, M5