This is a very frustrating site, fully of potentially dodgy sellers that want you to deal outside the system. Apparently they have never heard of phishing and scamming and are very offended when you try to protect yourself!
HOWEVER, if you can get through to a genuine seller, then everything is great and works as it should.
Sometimes the interface is a bit clunky and it is really geared at large or frequency sales rather than smaller/ less frequent sales.
So overall a mixed bag but can be very good