KE 747-800 all the way, definitely. One of the best J cabins and experiences of any airline, period.

Coupled with the KE in-flight service and food (great) compared to Delta's service and food (lacluster...at best), DL doesn't come even close.

The only downside is that KE cabins are usually scorching hot, like a sauna. But just ask the FAs to turn it down to something more comfortable, and they'll usually do so. Also, upper deck of 748 somehow doesn't seem to get as overheated as the other KE aircraft.