after the trouble with my Dell laptop, which was surfing with a promised performance of 300 Mbps, but despite 20cm distance from the Fritz! Box Fon 7270 only 65 Mbps could manage, I read a post in a forum of the built-in map that this scrap was.
The recommended Intel Centrino Advanced - N 6200 wireless - LAN Adapter Mini PCIe 2.4 / 5GHz 300Mbps brought immediately the desired performance. Then I had another card for a friend backordered.