Absolutely, you're adding great value to your network. You're stream is always full of quality content, and you're very actively engaged with your followers. However, you're producing high value signals that permeate far beyond Google+. That output is the reason Google put this service here - to extract value from the signals the users create. Nothing wrong with that, it's their job. In essence, my question relates to how much value a business or individual gets back. That depends on how you define value, and we're back to my question.
There is no answer because we're all looking to get different things out of the other end.
You've clearly found a network that fit, and your work is having a deserved impact.
Me... I'm just a geek, testing the signals, and watching Google develop their strategy. There's no value here...