I really don't understand why people make such a big deal about having to connect their Youtube accounts with Google Plus. The only problem with it is that there's no way to get to your inbox with one click of a link. Once you connect your account, it's not like you actually have to use Google Plus. The only feature that has to be used is the avatar, so it displays on your channel. Nothing else.
Also, newer features are being added for those who have connected accounts. One of those features is the Community tab, which you can find through the video manager. While not everyone has access to it fully, I've seen some who do, or at least have more features with it. I've read that this was apparently added for those with connected accounts, though that was a couple weeks ago.
The community tab will let you see things like those who have been subscribed to you the longest, those who have had the most activity on your channel, and possibly some other things that I won't know about right now.