Before we get into what's great about the revised mobile experience, let's recap a few points.
For whatever reason, Google has not created a Google+ application for Apple's iPad, nor for Android tablets. iPad users can slum it with the iPhone Google+ app, which is not optimized for the iPad; Android tablet users can use the Android smartphone Google+ app, also not optimized for tablets. These options are rather crummy.
Instead of using these non-optimized apps, I've always just pointed my browser at Google+ and used the mobile version of the web site. It's not perfect, but at least it is functional in that it lets you read posts, watch videos, and so on. You can't do fun things such as start Hangouts or upload photos, but at least you can read.
Fast forward to today, and the mobile Google+ experience just got a whole lot better. The website now looks and acts a lot more like the Google+ smartphone applications.
[ iPad or Android: Which tablet is right for you? Check out the specs here. iPads Vs. Android: 3-Way Tablet Shootout. ]
The home screen provides quick access to your stream, photos, circles, profile, and navigation. You can also access a settings menu for more fine-tuned control. Hit the stream button, and the site takes you there in a flash. It's much, much faster than before. You can shift between incoming posts from your own circles, what's being posted nearby, and what's hot on Google+.
It's easy to put up a new post of your own, though you still can't attach photos to posts from the website--you need use the actual Google+ application to upload photos or videos to the site. That's a pretty big limitation. I also find the user interface a bit awkward when it comes to responding to other posts. It takes several steps to +1 or comment when it should only take one.
I tested the new mobile web site on an iPad, a Motorola Xyboard, and a Windows Phone. The user interface is consistent across all three (Google says it also plays nice with the BlackBerry browser). While consistency is good, all the other platforms face the same limitations as the iPad when it comes to adding photos and videos to posts.
Of course, you can always switch to the desktop version within the iOS browser. This offers a richer--but noticeably slower--experience. It looks and feels like the desktop version, though you still can't start hangouts or upload photos/video. Adding comments and +1s to posts is easier, but it's flaky.
Bottom line: there is still no good way to use Google+ on tablets. You can gain basic access, but you miss out on a lot of the experience thanks to the limitations of the iOS and Android browsers. Why Google has forsaken tablet users is beyond me.
Windows is currently a nobody in the tablet market. That could change with the release of Windows 8, the first version designed for touch screens and the tablet form factor. With the new Metro user interface, Microsoft will try to serve both tablet and desktop markets. Can it succeed? Find out at our Byte webcast, What Impact Will Windows 8 Have On The Tablet Market?. It happens March 14. (Free registration required.)