Let's start with my thoughts on these platforms:
I have a hard time seeing how Twitter can used for anything really meaningful. It's a way to share simple thoughts, but you can't have real conversation. The most fun I've had with it is usually listening in on silly conversations between other people. This is a good way to share links, but it's not a good way to curate them. My Twitter stream changes fast enough that unless I follow the link when I first see it, I may never find it again. I've started misusing the Favorite button in Twitter to be a sort of bookmark. When there are posts that I want to come back to, I favorite them. I usually unfavorite them later, after I've checked them out more closely. This throws off Twitter's statistics, but it works for me.
I have two main uses for Facebook: keeping up with friends and family and getting news. The local TV stations are very good at posting links to their top stories on Facebook. This is also where I post thoughts, stories or pictures about my family. I tend to not post those to public forums (you're not going to hear much about my kids here, for example). Facebook has also been a good way to keep in touch, to some degree, with old friends from High School, or even earlier.
This is the part where I can hear you rolling your eyes (seriously, I know that sound). Yes. I use Google+. It is, by far, my favorite of these three services. I would love nothing more than to dump Facebook and use Google+ instead. Why don't I? All my friends are over on Facebook. Unless a giant, mass migration can be arranged, that's probably not going to change. So why do I like it so much? First of all, I like the interface. It's clean, pretty and it seems like everyone else is trying to copy them these days. Second, I actually like the way contacts are grouped into Circles. Sure, it's a bit of maintenance, but I set up a half-dozen or so circles when I started and I haven't felt a need to change them much. Third, I think the Communities feature is very cool and leads to some excellent conversation (depending on the community, of course). Fourth, it's photo editing and sharing features are FANTASTIC. I had my phone set to automatically send pictures to G+ and then they were really easy to share from there.
Here we are. Pros? Cons? I don't know yet. Keep checking with me and I'll let you know how it stacks up to the other information-sharing services that I use.