I liked Google+ (before they started hacking parts off it).
Platform wise it was way ahead of both twitter and Facebook (although FB have been stealing ideas back). However people didn't get that it was different. Most of the lively stuff happens in communities. You joined communities to get those posts in your stream because your mum/wife/neighbour weren't on it. That side worked really well.
However every "google+ is dead" story sends people away. They never got the traction to justify it as a social network (although I still maintain that wasn't the original aim, just one of the carrots to get everyone to ID themselves). User numbers weren't as bad as some of the press liked to suggest. They basically signed up, couldn't find their Mum and called it a ghost town. It wasn't great though and with people keep leaving it has all become a self-fulfilling prophecy.
I like it as a work network (facebook meets linked in), but more of the people I use it to communicate with have left, so I tend to use it less. Not sure I'll replace it though. Twitter is just an annoying torrent of unstructured noise after g+ and facebook is the usual bollocks.
