I thought it was a far superior UI to facebook when it launched. I tried to use it but the gravity of the network effect was too strong on facebook's side.
In the end I'd rather if both had failed. Although one can argue that they actually did. But that's another story.
I very much wanted Google Plus to succeed. Circles was a great idea in my opinion. Google Plus profiles could be the personal home page for the rest of us but of course, Google being Google...
That being said, tying bonuses for the whole company on the success of Google+ was too much even for me.
I very much wanted Google Wave to succeed. It seemed like a really cool way to communicate.
I guess we sort of got it with Slack though