I have my rack off to the side, & my power amp in between the speakers. It "looks" much better that way too, IMO, if that matters. I don't even have real expensive IC's to the amp, & I think my system sounds fantastic. And I know it's not about looks, but if you have a great looking expensive power amp, it's nice to "show it off" by placing it between the speakers.
Oh, & whatever extra you spend on IC's to the amp, you can save by using shorter spkr. cables......