How was Einstein as a person?

A warm hearted person.he was very smart with an IQ of 160. He could have been even smarter if he had a higher IQ.

A real nice guy; he'd even answer letters that children wrote to him.

Einstein was 5'9" tall with a sense of humor.

I want to remind those who are short minded the fact that it was him , requested by L. Szilard, who addreesed a letter to the USA president , for the sake of informing him that there was a real possibility of designing and manufacturing nuclear weapons of enormous disrupting potential ( this led to the approval of the Manhattan project)

But once the bomb prototype was testet in New Mexico, he was not among those scientists who signed another letter to the new USA president H. Truman inviting him not to use those bombs against Japan

Later on he jumped on the wagon of conformism

Well...

he left (abandoned) his first wife and children to marry his first cousin.

He was a complicated human and his sense of humor was pretty astute. Yes, I would have liked to be his friend.

well if you like to be around aerospace engineers and discuss with them how you can get more fuel efficiency from the engines by tweeking your math formulas, then yes you could be friends with einstein, otherwise hed bore you to tears.

he was a crazy mofo