I've never heard of them.

are the complaints about stuff not turning up, excess postage cost, or postage time? I find some complainers especially when it comes to postage time are often blowing things out of proportion.

I made a purchase on ebay just recently, the seller messaged me practically begging for positive feedback and high star counts on postage time saying that being regular international post it would potentially take several weeks and to please be patient etc.
there was even a note along the same lines in the package when it arrived.

I think it took maybe 7 business days to arrive, and it was well packed, if he's had a hard time from other people on that level of service then there are definitely some complainers out there.