If you're spending 25K on your video presentation, I find it hard to believe that person is not spending a good amount of money on his audio setup. It might not be separates, but I seriously doubt it's not going to be a top of the line receiver.
As to the separate versus receiver arguments and...
Edwin,
If a person is dropping 25K on a projector then they obviously want the best video presentation. Why stop there by not investing some monies into achieving the best audio presentation?
I have the Yamaha 3060 too, but except for the four Dolby Atmos channels, I have a separate Outlaw amp to power up my other 7 channels as well as my two subs. It's quite simple, a dedicated amp is better suited to power up my speakers than my 3060.