IMO, whichever amp better handles the complex load of a multi way speaker, typically will sound more powerful than an amp that can't, regardless of rated output into a 4 or 8 ohm resistor.
Reading Spec Sheets
I often look at watts, but what about current. Is there a way to tell if an amp is high current or not. The reason why I ask is I have had amps that list more watts into 8ohms or 4 ohms, but did not sound as powerful as amps with less watts. I suspect the reason is current. So is there anything in a spec sheet that would tell current capablities.