The site often requires login even if you are not buying anything but just looking.
Once you find something and open the product page you do not know what category it falls into, then it is difficult to find a cheaper quality or more popular alternative.
When you are finally planning to buy something, but want to read some useful reviews, it will offer you hundreds of useless, worthless reviews, without any filtering or sorting option, even if it is available and you can rate every review, but the only sorting option is by date.
And the fact that the same product offers dozens of traders and the actual selection of products is often poor to not even talk.