That is definitely an improvement, although the document you linked to suggests that the old-style records would still be used for some purposes. If the language already has tuples there's really no reason why it shouldn't just have tuples with a fixed set of named fields.

The quirks of JavaScript that you mention never bother me at all in practice (and yes, bringing up 'with' is a very cheap shot, and Erlang's string handling is pretty wacky too), but I remember that not having real record types was a serious pain point.