Do you mean it is a toy because it only works on database dumps or..? I can imagine that querying, filtering and traversing relations will be harder with only a textual dump.
You have a DBMS available, but all you ask from it is a dump of all data in a format that can only be used as an archive or transfer format. And yet you think you can process this data reasonably?
I guess your "you" is not directed at me, as I basically wondered the same.
Replibyte seems like to use a highly unpractical way as I explained, but I meant to ask wether you only found the implementation to be bad, or that you also found it lacking in other terms.