Despite the fact that it's feeling a bit like a ghost town over there at the moment, since they're limiting the number of users for now, my first impressions of the service are generally positive. The highlights so far:
- A clean interface. Google has always been good at fairly minimalist, clean web design, which I really appreciate.
- Easy integration. Since Google+ is connected to my Google account, it will be really easy to add people already in my Gmail contacts list. Also, a new top-of-the-page menu bar now shows up on all my Google pages (Gmail, Reader, iGoogle, etc.) with the Google+ share box and notifications info. Since I spend a lot of time on Google Reader this is great for me. It's also connected to Picasa, so if you already use that site for photo storage it'll be easy to share those pictures.
- Privacy control. Every single post lets you easily pick who to share with. No more defaulting to every person you've ever met. You can also decide for each piece of information in your profile who has access to it. Want to share your favorite food with the whole world but keep your job title private? No problem! You also don't have to be a sleuth to find the privacy controls, they show up at the point of editing your information.
- Circles. These are a little like Facebook's lists of friends, but they're so much easier to manage, with an easy drag-and-drop interface. They let you group people so you can easily share with that particular group. Unlike Facebook, which only lets you exclude lists of people, Google+ lets you decide which circles to include when you share something.
Edited to Add: TechCrunch has a good review that sums up my experience pretty well.