I like this site because you can find some honest sellers selling their authentic, pre-loved items at a low cost. However, I've actually seen some very blatant fakes, and some other questionable items despite the site's claim of using algorithms that catch 99% of fakes. Some sellers sell their used items at reasonable prices, and others sell their items at higher prices than what you can buy brand new on a designers website or store (e.g. Louboutins), which is just ridiculous. Shipping is slow if the seller chooses to use the Tradesy shipping kit, because Tradesy must send it to the seller once the sale is confirmed, which adds about a week to the shipment time. Both the seller and I, as the buyer, were totally underwhelmed with the "beautiful" shipping kit. It was a plastic shipping bag, bubble wrap, and tissue paper. If you are going to sell something, it is best to just use your own shipping materials and get reimbursed.
With all of that said, if you are going to buy on this website, I would spend the time researching the items you want to buy, to make sure you aren't buying a fake. You can also use some authenticating businesses (e.g. Authenticate4you) to authenticate the item before you make the purchase. I purchased a pair of Louboutin flats and was pleased with the sellers communication with me, as well as the shoes. I would buy again from this site, but be just as cautious as if I was buying from eBay.