Drupal 8 will be stable...today, tomorrow, and probably until it will be declared EOL.
It’s true that the Release Candidate versions had some stability issues, but that’s more than normal for any RC. Those who did at least a software in their life will understand the release life cycle and will probably agree that such a gigantic task requires a lot of time and patience.
Keep in mind that this is not a simple software, but a complex content management system in a continuous change and transformation. After the RC period, Drupal 8 started as a stable, reliable and easier to use CMS perfect for almost any type of platform.
More about a software’s release life cycle:
Almost all softwares and programs out there have approximately the same life cycle. After weeks, months, or even years of development, a software is finally released. The first release if usually done in a Release Candidate version.
Everyone should understand that such a release is not like getting a fruit cake out of the oven.
After release, a software is not ready to be “consumed” by everyone. The definition states that an RC is a “beta version with potential to be a final product”. It is mainly a stage of product stabilization, so Drupal 8 was more than NORMAL.
Just to get things straight, before going full live, any software must first follow these steps:
Pre-alpha → Alpha → Beta → RC (Release Candidate) → RTM (Release to manufacturing) → GA (general availability) → Production
Some steps may be skipped, but even so, you will at least have:
Alpha → RC (Release Candidate) → GA (general availability)
In the case of Drupal, lots of stability concerns have been expressed in the RC period, as it would be normal to be done.
As Drupal 8 improved more and more, the worries and the stability questions started to disappear.
At the moment, Drupal 8 is more than stable and can be used without many major problems.
Bug fixing versions are released monthly and are bringing some amazing features. The majority of modules have been ported to Drupal 8, making it even easier to use.
We at Softescu have used it for almost all our latest projects, and it is a great CMS for both pros and non-pros (editors). It’s true that at the beginning it may seem a bit difficult to grasp, mainly due to the differences from Drupal 7. However, it worths investing some time in learning and experimenting with Drupal 8, no matter if you are a Drupal dev or not.
For more info about Drupal 8 releases, also check out the Releases for Drupal core.