Their sub-fleet of 757s that serve Hawaii are marginally (and I do mean marginally) better in F than the standard Y seat. If you can snag an exit row in Y then that's actually probably the better ride than up front. The sub-fleet is ex-ATA and the seats do have legs rests and maybe an inch or two more legroom than their other 757s, but they're sort of worn and pretty outdated. Overhead video and no individual air vents.
They also do run 757-300s on the LAX-HNL segments as well which I prefer over their 757-200 subfleet. The 767 is definitely a better experience with AVOD if you're willing to route through HNL to do it. Delta, like most other mainline carriers, don't really put premium product on their Hawaii segments. Hawaiian is an exception, and they're starting a new LAX-OGG flight. I've seen them run some great FC deals in the past so may be worth checking out. Of course no mileage earned for those flights. Their FC is a bit better than the other carriers but still not up to the LAX-JFK BusinessElite level.