KLM
Worst: need to spend (large) amounts of points for connections to AMS on award tickets (while those are very cheap if buying cheap econ tickets.
Bad: low earning (no real miles earning) = expensive award tickets
Bad: no automatic upgrades except in US, no system wide upgrade vouchers for elite tier members, no Million Miler status (would probably equal something more like 1.5 million real miles)
Best feature: lounges