Well, did not expect this release to take so long, but as release tend behave, this one just kept growing.
In the end, it jumped the revision count by 800 points, introducing 168 new features and fixes - slightly more than the 1.0 release had (which was a ridonculously huge release).
Here is why you should upgrade
As is obvious from the release number, this release is about refinement, not necessarily big new features. 107 of the items in the changelog below are bugfixes, which is a pretty good reason to update.
However, there are quite a number of very noticable new features - streamlined administration and the new option to have the registration form right on the confirmation page - but most of it sits two layers below, like the LESS preprocessing or the form validation during checkout.
Joomla 3.0 compatibility was long overdue and has now arrived, including switches for bootstrap and jquery for the frontend template.
How stable is it?
At least as stable as 1.0. We've been using it internally for quite a while (and a lot of clients) already, so it is well tested. I've spent the last month working almost solely on ensuring that there is no bug left (whether major or minor).
Then why is it only a "release candidate"?
First off - there are a couple of non-critical features I still want to get into 1.2. Mainly a number of payment processors. Apart from that, though, our past experiences have shown that no matter how hard we look, it's simply a law of nature that we will miss a couple of things. So as always, a release candidate is a "fingers crossed" release. You can be sure that we will fix any bug very quickly, though, so we will post updates as soon as possible, if need be.
Two notes of caution: First, we are no longer distributing .tar.gz files. I've had the joomla installer die out in various, colorful fashions on tar.gzs and it's simply not something I can fix with the current setup. This means, however, that second the package size is now 4MB. Please make extra sure that your server allows for an upload of that size - if necessary, increase the upload and execution time maximum in your PHP configuration.