Is it best to use a 5-channel amp for biamping??

I would like to read the response to Arthur's statement regarding the improvement with more power, would like to add a little twist to it.... if your 5 channel amp is struggling to handle the speakers (using one channel per side), so using 2 channels of the 5 for each side (L & R) wouldn't it be expected to have a more noticeable effect (common sense suggest dynamics) with this scenario? Thanks
Luis

Thanks gentlemen!
Luis

Sean:

That's what I call "boiling it down" advice!!!!!!
I've been sticking to a lesser amp tweaking the whole system while building the "critical mass" and take the leap!