Any flaws worth taking?

[True Story]

I was offered Plasma Weakness in Byzantium but I don't know how much worse plasma damage might factor later in the game. 

I hear the - 1 flaws take away 5-7 points from their grouped skills. 

[Rangertal]

All of them. I took the first 5 I could get with my 2 hand Science Build. But at the end of the game I didn't really need them, it just help to get my character to 1-shot awesome a bit faster. (Super Nova) 

On that note, 2 Hand Science with the Prismatic Hammer is by far the easiest mode in the game, even on Super Nova. I enjoyed it immensely.