I think Google+ may just turn out to be the best social network of them all. I also think though that Google+ has a lot of headaches currently and unless you're ready to deal with them you should stay off Google+ for now.
Here's my short list of Google+ problems. If you can't live with any of these: Don't try to get on Google+ yet. Most of these will be fixed. Keep in mind that some of the potential policy problems may not be changing anytime soon... if ever.
1) Google+ is Beta Software
The very first thing you need to keep in mind with Google+ is that it's beta. When I say 'beta,' I mean it's as dependable as a car with a serious engine problem. It may get you to work on time... or it may leave you by the side of the Internet highway wondering why there's smoke coming out of the engine. In short, you can't depend on Google+ yet. While I haven't had it outright fail on me, I have people come and go out of my Google+ Circles and posts disappear for hours at a time.
At present, Google+ just isn't very dependable. This will get better, but if you come in expecting it to run smoothly right now, you've come to the wrong network.
2) No, I mean Google+ really is Beta Software
Since its beginning, Google has released beta software. Often, even in beta, these programs, like Gmail, were quite good and works in the same way from one day to another. That's not the case with Google+.
Even when Google+ works perfectly, it's always changing. What worked one day may work another day in an entirely different manner. Most of these changes are for the better, but you can't just go on Google+ one day and expect it to work the same way it did yesterday.
This is especially troublesome for people who are using Google+ Web browser extensions. There are a lot of them out there, and some are quite good. I haven't even tried to list some of the better ones though never mind review them. That's because one that will work one day won't work the next. Or, Google+ may adopt its functionality into the network itself leaving you with a tool you don't need anymore.
Eventually, thing will settle down with Google+ interface and functionality, but we're still a long way from that happening.
3) Real Names
How comfortable are you with having your real name, or the name you commonly go by online anyway, being permanently attached to your Google Plus account? If you value you anonymity; if you like keeping a firewall between your real identity and the one you use online, Google+ is probably not going to be for you.
Violet Blue has written about this real names problem at length. While Google has made some changes in how they're managing Google+ names, they're still leaning towards having users use their real name, or at least the name they're mostly commonly know by on the net. This troubles a lot of people.
I don't think this problem is going to go away. That said, it's even worse on other social networks such as Facebook. There, Facebook's former marketing director Randi Zuckerberg announced just before she left that "I think anonymity on the Internet has to go away."
If you really value keeping your privacy and you want to be on a social network, I don't think any of the larger social networks will prove to be a welcome home. Instead, you should be looking for federated social networks. These networks, such as Disapora, Hubbub, and StatusNet, are still coming together. What they have in common is that they put, to one degree or the other, the servers, the software, and users identities into the hands of the users themselves. If you value privacy, it's these networks, not the Facebooks of the world that you should be turning to.
4) Account instability
Google has been kicking people off Google+ for not using their real names, for violating the Google terms of service, or-for all we can tell--looking funny. Or, as Google put it when they explained why Blake Ross, a Facebook executive, had been kicked off, it was the fault of "an account deletion bot."
While I haven't had this problem, I've heard enough stories from friends that I can tell those account deletion bots are seriously misbehaving. While you can get your account back, with all its data intact, most people don't need this pain in the neck.
5) Google+ Mismanagement
Underlying a lot of these troubles is that Google simply has not put enough thought into its policies. They also don't have anything like enough real people managing the system. Even as Google relies on bots to take care of day-to-day management, Advertising robots, fake users, and all the other junk you find on other social networks are showing up.
Before Google+ is ready for hundreds of millions of user, or even the 25-million it already has, Google must establish the social network's rules of the road. The company must also put in the management and support it needs to make sure everyone understands the rules gets along reasonably well.
This problem isn't too surprising. Google+ is growing faster than any other social network to date and Google didn't expect it to grow so fast. But, just because there are good reasons for Google to having these troubles doesn't mean that the problems don't exist.
Despite all that, I love Google+. But, if you can't live with everything I just listed, don't raise your blood-pressure by joining it. You'll just get ticked off and what's the point of giving yourself misery? Give it time though and eventually it will mature to the point where I think almost everyone will love it. But today? Today is not that day.