The animation of TAS gets a hard time here (and other places, I guess), but for the early 70's TV market, it was pretty standard. At the time, it didn't stand out as "bad". Actually, Filmation had some of the best character renderings and backgrounds in the industry. Agreed, they took a lot of obvious shortcuts, which is a Filmation trait, such as constantly reusing the same angles, and movements, focusing on an ear so a mouth wouldn't need to be synced up, etc. You can pretty much see every drawing of the main cast of the entire series in a single episode. But, as a kid, I barely noticed it. Actually, I did notice it enough to influence the way I drew homemade comics. The same angles and poses.
But look at other Saturday morning shows of the time. They may have been more fully animated, but the images were inconsistent and the movements less fluid. IN later Filmation efforts, every so often - and it was rare - they would use rotoscoping. I don't think it was used on TAS, however. But pop in a DVD of The Superfriends from Hannah Barbera, and see some of the sloppiest animation ever aired. Or think back to what else was on Saturday morning in 1973 & 74: Yogi's Gang, Inch High Private Eye, Emergency Plus Four, Goober and the Ghost Chasers, and so on. None of these had images nearly as nice as Filmation.
What I loved about this period, was that the schedule was filled full of live action TV shows adapted for animation, many with the original cast voices. Trek and Emergency Plus Four were two, as were The Brady Kids, The New Adventures of Gilligan (Gilligan, Brady Kids and Trek - all Filmation), The Partridge Family 2200 AD. Then there were those without original voices, but still based on earlier 60's shows, like Jeannie, My Favorite Martians, and The Addams Family. There was even a pilot for a Lost in Space cartoon, with only Jonathan Harris involved, but it stank on ice. Strangely, aside from that one attempt, the Irwin Allen shows were not mined for animation. Those had evolved (if that's an appropriate word) into live action cartoons and would have been perfect for Saturday morning.
I loved it all, because when I was 6 or 7, the 60's shows were hugely
popular in syndication. Trek was just one that lived beyond reruns, but at the time, nearly everything
fantasy related from the 60's was a huge hit with kids, which spawned these spin-offs. Adults also got into them, if my family was any indication, which was funny considering prime-time television had started to become "relevant" at the turn of the decade. Looks like some of us weren't ready for the change. I'm still not. When I see a listing of the fall line up in 1966, I weep having missed it. No less than eleven prime time fantasy/sci-fi/adventure shows on the air. Some even conflicting with each other - that would have killed me.
Anyway, sorry this fell off topic. Yes, TAS on Blu-Ray would be great, and put all of my original cast Trek in that format. TAS is the lone holdout.