Marriott have 10% discount with GC. Marriott points easier to redeem and more value. I am Hilton Diamond and Marriott PP. Rarely stay at FS facilities so upgrades are basically moot. However, I have been getting Marriott upgrades whenever I do stay above a Courtyard.

I like Hilton for the AXON discount. Stay there whenever there is a promo that makes sense.

Regarding breakfast, I was at a Marriott property with a lounge and breakfast. Never made it for the whole week. Even if I can make the breakfast, I just find point redemption value more important than breakfast. IMO, Marriott points are far more valuable than Hilton.