First off, let me say that I think having followers is important, and these days, i think most of your followers, if not all of them, will be on at least one social networking site.
I think Jetpack has a lot of great features. It works great on it's own. But one thing I think may be important to some, is that the current social capabilities of it (comments) don't really, from what I can see, allow a admin to track their users. Over the last week or so on my freshly installed wordpress site, I've been testing different social logins and ways for visitors to comment on posts. I think the Jetpack comments looks excellent. My favorite part is the Post Comment button because it looks a lot nicer than the other plugin I find just as useful for the comments (WordPress Social Login)
As a login plugin, I think the WSL plugin is awesome, Just click on the social network icon of your choice, and you are done registering on my site. This is pleasing! It also merges users if duplicate email addresses are found (for most social networks as some API's like Twitter and LinkedIn don't pass the user's email to us).
What don't I like about the WSL plugin? Twenty Eleven theme it uses does not have perfectly aligned Post Comment button.
What don't I like about Jetpack? If unregistered posting is allowed, this invites spam and loss of a potential follower. If I require registration to post, now visitors must go through the task of registering.
Now at some point during the last 2 days, I was working with so many plugins and API's that I started confusing myself. My plugin list was ugly. lol. At one time I actually had WSL and Jetpack running at the same time. Surprisingly, they didn't seem to conflict with each other and slow things down. I'm going to test that one more time today because I think it may have actually worked.
Ultimately I would rather not have to run 2 different plugins. Hoping Jetpack someday has the Login capabilities
Sorry for the long post. I'm at work with not much to do and thought I would put my 2 cents in. Not sure where else to put it on the site.