Google+ introduced Communities a short while ago, and it changed everything. Before, as a G+ user, I roamed in a white void of nothingness. There was no "friends" to share stuff with, because heck, no one but real geeks paid any attention to G+ after the initial "invite-only" fad. I knew there're people out there, but without an initiative, I had no reason to reach out to any of them. Communities changed all this. I was able to search on topics that interest me, from the uninspiring tech topics such as Android to actual interests such as coffee and primal diet. I was able to post on each communities different threads, and I would be getting constructive responses because the people reading them would have the same interest as me.
Here's an example, I posted a photo of a box of disposable drip coffee on both Facebook and G+'s Coffee community. On Facebook, I got the usual "cool", "what's this?" from friends and maybe friends of friends. On G+, I invoked fellow coffee lovers who provided me with actual useful insights as to how to best use this box of coffee.
Another example, I joined this Vibram Five Fingers community, which was very new and got all but 6 members. Even with very limited action in this community, I was able to discover an online store that was doing some big discounts on VFFs.
I think to sum it up, G+ Communities provided a channel for much deeper discussions whereas Facebook comments are either all too shallow or flame wars.
I spend a lot of time on G+ everyday now that I have joined a good dozen or so communities. I have learned a lot in topics that interests me, and I strongly believe this is a much better use of time than browsing people's pet photos or commenting on their status of how life sucks.
I urge all of you who have given up on Google+ to give it another shot, purely in playing around with Communities. I promise that you'll be pleasantly surprised in how much an addition of one simple feature can help you learn so much more.
(btw I don't work for Google and I get nothing for promoting their service. But I do get great gratification by knowing more people are taking advantage of this and therefore getting to learn more about stuff that they care to learn about.)