You can alleviate the oddity of the look by picking a color that might blend in better with the slope. Just a thought. And not saying the in-ceiling will sound bad. Just that in terms of pure performance, you will likely enjoy the Qs more. But we are all familiar with the trade-offs needed in HT.

Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire