For 2/3rds of the series basically nothing fucking happens OR it doesn't really matter much in the long run and could have been easily skipped.
The animation quality switches drastically from episode to episode. Sometimes you'll get an absolute insanely good shot (for TV cel animation in the 1970s) and other times the cels were covered in so much dust/hairs that it was distracting, especially during scenes where the characters would just be sitting down and talking with little to no movement body wise.
Personality wise each character is incredibly simple, even one note at times. I won't mention who, but there is a very prominent character that is introduced midway through the series who I expected to gain some character development and stop being such a fucking BITCH all the time but...She just stays basically the exact same for the next 30 episodes??? Although I suppose her behavior becomes more comedic, and I can't deny that I laughed at her outbursts.
On top of everything there are some issues due to the culture of the time, it's nothing too large but there is blatant child slavery so, uh, y'know. There's also some minor sexism (though, for it's time it's pretty progressive overall)
I still enjoyed it, but I have to admit that my taste is a tad difficult. I wouldn't reccomend it exactly...but calling it bad doesn't seem right either. I'd say give the first few* episodes a watch at least, as they are pretty comfy and just pure slice of life (up until Heidi leaving to Frankfurt specifically) After that I reccomend watching the movies instead as they are much more compact story wise.
