I just ordered the 7075 and I am planning to use it for my 5.1 HT setup.
Will the SQ be improved if I bi-amp the Klipsch speaker using the 2 extra channels?

It'd be worth a try, at least - may be some subtle benefits to the extra power.

I have revised and added to my comment, then moved it in the Saloon to the Single vs. Split Pathways (bi-wire, bi/tri-amp, etc.) discussion.

Great explanation.

That is why Meridian's active speakers with only 75 watts/driver amplification and average efficiency, can sound so loud...

SP72, have you tried the Klipsches in a biamp setup yet? If they're not the all-hornloaded classic Klipschorn but the more recent hybrid models, and you're passive biamping, you may find a drastic difference in sound level between the hornloaded tweeter section and the (I think) bass-reflex woofer section. Klipsches, of all speakers - though the current JBLs may be another example - might have to be active-biamplified to work right, with each channel's level controlled separately by the active crossover.

SP72, I was wrong in my last post - passive biamping of Klipsch or any other speaker systems wouldn't change the relative levels of the tweeter and woofer sections, since the systems' passive crossovers would still be functioning. No worries then. Good luck and let us know if you can hear any difference.