I've only used one of the bits but they seem to be of acceptable quality. For the price I don't expect longevity. I'm just a home user so they will work great for my purposes.
Pros
Versatile Working Tools: This tenon and grooving router set is truly versatile for your added convenience. Works great with all types of materials and surfaces such as wood, MDF, chipboard, plywood, board, softwood, hardwood and many more.