I ditched Facebook very shortly after G+ opened up. Comparisons to Facebook and post-counting completely miss the point. The experience on G+ is entirely different. Facebook was a continual stream of "If you don't repost this link, you are a jerk", "Look how much bacon I ate!!!!" and "I am having the worst day ever!"
On G+ I have a (comparatively) small circle of friends and we discuss music, politics, art, keep up with each other's families. I follow a few science bloggers, geeky personalities and a few generic music and science related searches. All of it gets fed into different streams, I can keep up with the important stuff and dip into something random that will almost certainly interest me if nothing else is going on.
G+ seems very well designed for encouraging more thoughtful content and discussion. The total throughput might not look as active, but I get one hell of a lot more signal. Not to mention that FB's interface makes my eyes bleed. G+ is almost relaxing.