I recently purchased a Yixing pot and I'm quite happy with it. It appears to be well-made (some minor flaws here and there, but visible only under close inspection), the lid fits very well and flow stops when the spout is covered. The lid does not fall out when the pot is vertical. The body certainly SEEMS like it is made from a Yixing clay - it has shiny specks here and there. It is an unusual color, and I think this was a specific aim of the maker - it is a strange greenish-brown, very "old looking." It makes a mean pot of Tieguanyin.
However, it doesn't seem to have much of a "ring" to the body when I do the scrape-lid-around-rim-of-opening test. It just sounds like scraping clay on clay. What, if anything, does this say about the pot? Incorrect firing? .