Below is a post I wrote on Google+ today that got so many likes and shares that I think it speaks of the first experiences of many of the beta testers. Feel free to add your own thoughts.
I just worked out why G+ works. It's the only social network that treats you like an adult, but doesn't expect you to act like a square. On Twitter and Facebook, you're constrained by things like text limits (both), number of allowed posts and follows (Twitter), people you're allowed to connect with (Facebook), etc. On LinkedIn, you're meant to be on your best behaviour, and only talk about business. However much they try to make that place chill out, it still feels like someone's photocopied their bum at the office party whenever they make a joke.
Google+ however has ... no text limit. It encourages you to meet new people, like Twitter, but it helps you to segregate them into groups if you want, like facebook. People are treated like adults. Finally.