I've thought about this, haven't tested it. I have a 1x12 50W combo, the 12" speaker is rated at 60W, and ohms matched with the power amp (8 ohms), it's getting the full 50W of power to that 1x12 speaker.
vs 2 x 4x112 cabs, each 16 ohms; with 2 of these cabs, it's 8 ohms total. with a 100W head, each speaker is getting 1/8 of the 100W @ 8 ohms, so you can use speakers with a much lower power rating.
I have a pair of 2x12 cabs, rated at 8 ohms each; combing them for a 4 ohm load, which gets even more power out of a 100W head, with each speaker receiving 1/4 of the 100W amps power at 4 ohms, which requires speakers that can handle more power than speakers in a 4x12.
I'm guessing that power distribution is going to effect the how the speakers are driven. Different power ratings of speakers are going to reflect how they respond to a given power signal. Not sure how to compare short of having 1x12, 2x12 and 4x12 cabs loaded with the same speakers and using them under different ohm loads; I expect they will sound different...but how much is due to the amp power, ohms, the speaker cab...
it feels like I'm getting into TGP "voodoo" territory now; all I'd need is a cryogenic, directional power cable...