Opinions Wanted: Vivitar 2x Macro Focussing Teleconverter

[Scott Nelson]

I seem to recall hearing good things about this TC, but a search of the
PDML archives didn't turn up anything useful.  Has anyone got one?  How
do you like it?  If I did pick one up, I'd be using it with a 135/2.5
and a 50/1.7.

-Scott