Esrin / Chinese Satnavs

Looking at buying an Erisin 1 din GPS system from ebay. I have searched around but can’t seem to find any actual user reviews on them. There seems to be a few different models available, has anyone bought one and are they any good■■?
I am mainly interested to know what the bluetooth hands free audio quality is like with regards to the mic.etc? (currently have a parrot CK3100 fitted, which hopefully can be removed if the hands free is ok on the satnav unit).
Also are these units able to run primo 2 ok?
Thanks for any advice.

I doubt anyone has bought one and been impressed enough to write a review.

Go with the well known makes, TomTom, Garmin etc.
Those are well known, because everyone uses them, because they are good. Updates, poi files etc are easily found and installing them is easy.