hmmm well my point of view ! Google+ & Facebook Both are amazing social networks ! Both have great features & service those always entertainment to fans ! Google+ is little slow than Facebook & one more thing about Google+ is ! Google+ is very strong & hard in cell phone but Facebook is every soft & easy to use in Cell Phone! So it's also a reason !
I prefer both Facebook and Google+ account. Both are very important according to my point of view. But I slightly in favor of Google because Google+ is helps for authorship. If you want get some good benefit of authorship.