Hi tealboy1,
As I wrote in reply to one or another of your past PMs, all of the eyepieces for the EDII will fit the EDIII, 78ED, 82ED, and 50ED and vice-versa. Straight or angled makes no difference to the eyepieces.
As I also wrote, the 82ED is fully multicoated with more modern coatings, so it should have better transmission than the 78ED, but I don't see a practical difference. In very low light, the 82ED will be slightly brighter than the 78ED because of the larger exit pupil; the difference is small but detectable. Main practical advantages of the 82ED are better waterproofing and built-in extendable lens hood. I own both (They were selling 82ED with 25-75x for <$900 new immediately after the model was discontinued, so I picked one up as a spare) but I end up using the 78ED more just because I like its telephoto lens style handling (due to tripod foot behind focus collar) slightly better.
The other differences between the 82ED and 78ED are, most days, even less consequential for me. One of those other differences is that the 82ED has a nice stay-on case design. The 78ED wasn't provided with a stay-on case for most of its history but one was available eventually (exceedingly rare). I don't like stay-on cases and prefer to instead wrap my scopes with McNett camo-form.
--AP