I just purchased this puzzle for my 16 month old daughter who enjoys it. However, the colors of the plug and the hole are supposed to match and they don't. Some are just very different shades and two are different colors altogether (purple versus blue/ orange versus red). Since color recognition is a fundamental aspect of this puzzle, this seems to be a significant flaw.
I also found as another reviewer did that the pieces don't seem to have been removed and cleaned after the jig cut them out. There is particle board dust that seems to keep wearing off with continued use even after it is cleaned with a damp cloth. This can be considered a small trade off for the price of the toy since it is so functional and educational.
However, the only concern I have with the dust is whether there are any chemicals from glue or other materials that might have some degree of toxicity. The pieces are in no way deteriorating of crumbling apart; there is just dust that my daughter found fascinating and began licking off her fingers.
The pegs to hold the pieces are perfect. The pieces fit well, not too loose, not too tight. I really like this puzzle for my daughter and hope that I can get it exchanged for one that has accurately corresponding colors.