@WS64: AFAICT, switching to a proper json decoder would be probably faster if there's a C backend, and handle the unicode issue properly.
EDIT: Barring that, looking at one should at least give you an example of how to handle escaped unicode sequences.
EDITē: For example,
dkjson's unichar function seems to handle it in a fairly concise manner.
Code:
> print(unichar(0x00e9))
é