I'd swap to KE if you can. Normally I actually quite like Delta's TPAC service, but the HND route is the exception with the limited redeye service. KE will have a much better onboard experience in comparison. (And the 767 is my least favorite DL business seat.)

The only thing to think about is lodging costs in Tokyo; since Haneda is so much more convenient, if you're looking at a midnight departure one day ex-HND or a midday departure the next day ex-NRT, you might be paying for an extra night of hotel without getting much additional meaningful time in Tokyo. That might outweigh the better onboard service of KE for you.