I'm not a VC, but, to be comprehensive, you'll need to put the negative impact of the suit publicity - whether she wins or loses - on her career against what she might gain by winning.

If you sue McDonald's for food poisoning frivolously, have the bucks to do so, and are somehow immunized against a countersuit, there's no downside.

Pao, win or lose, is going to have a very different VC career than if she never filed suit. That's a pretty big downside.