The quality, mechanics, haptics, materials, optics of the adapter are - as we M and the EF-M lenses are the ones from the EOS usual - outstanding. High quality product!
By the way, the EOS M kit with the 22mm pancake lens, this adapter is included. Whoever wears the idea to take advantage of the currently unbeatable prices for Canon EOS M kits, possibly should catch up the purchase of the kit with the 22mm fixed focal length lens into consideration. I think this is the best date for EOS M door. The kit is currently always as lightning Amazon offer for less than 400 EUR (incl. Body, EF adapter, 22mm lens, Speedlight flash) available.