I saw these a few years ago, and any true Batman fan owes it to themselves to see them, even if they're not particularly good on any level. They're fun as curiosities, and I'm fond of the roughness and simplicity of them (qualities Batman lends himself to more than any other superhero mainstays), but they're goofier than I'd prefer to see. I'm not talking about production value or anything like that - I took them for what they were, didn't expect major motion pictures - but more that I couldn't take Batman or Robin or Gotham or anything else seriously. But then, by the time I saw them, these weren't for me, they were for kids. Again, I enjoyed them as curiosities, and I'm glad I saw them.
Interestingly, Frank Miller has said that these serials are his favorite interpretation of Batman in live action.