Linenger has an inflated ego, Shannon Lucid made a great flight, Michael Foale is the proverbial good astronaut (normal, he was born in Europe:-), John Blaha noticed his depression and faced it and overcame it. It's quite revealing that most US astronauts who had spent a long time aboard Mir, quit NASA right after.
And, luckily, George Abbey isn't choosing who's going to fly and who isn't, anymore.

The most important lesson: NASA sisn't prepared to send astronauts to Mars yet. If they don't get along with each other, the mission will be a failure. Mir has tought us lessons but has NASA learned from them?

Raoul