The 767 domestic is more cramped up front. The sides are not as wide and after dozens of flights on both types, I swear the legroom pitch that Delta claims on the 76Q is not accurate; I feel more cramped at my knees as well. The only remedy is the bulkhead seats, especially the 2 middle seats on the 76Q

The nice thing about the 76Q is it's a widebody. It's less enclosed. But based on the seats, I would chose the 75X.