Have both now extensively compared directly with each other (also based on the values of InSSIDer). Sober result: the small TP-Link TL-WN722N receives 1) stable and 2) about 3-5db better ... in any situation.
2 stars that the WN8200ND 300Mbps and the TP-Link TL-WN722N 150Mbps only has ... who just need this feature ... The WN8200ND is already on the return path ... had I really hoped for more ...