Having flown in D1/BE on the 777, 763 and 764 I think DL has a decent international business class product. Seatguru actually places DL's seat wider than EK, but in all reality both cabins are 1-2-1.
It would surprise me if EK didn't beat DL on the soft product, but hard products aren't too far apart. The TV screens on the 777 are pretty bad.
I think the trip report was fair to both airlines. Now EK's first class cabin is a different story, but I think in terms of J, DL has a decent product.