Well, of course the animation isn't perfect, this is a 1974 TV cartoon, and we know all the tricks used to make it cheap enough to be profitable, I mean, that's what the technology of the time allowed. The bike jumping the cars animation is used in almost every episode, and it seems bad by today standarts, the bike flies over the cars at 10 mph. But all we can do is to think "ok, it's 1974, we forgive you".
The plot for the episodes is actually good, but it does get corny and silly sometimes. All in all, it's quite entertaining, and yes, it's watchable.
If they remade "Devlin" with the proper animation, and working harder on the episode plots, it could be a hit.