This version is not recommended for production.
The code is stable and expected to behave but it is a 0.0 release ...
Would you ever trust a 0.0 release in production ??
Please be aware that the configuration format changed in non-backward compatible ways. If you update you will need to change your configuration to the new format / parser.
Unless you need some of the features which can not be back-ported to the 3.4 branch (for example when using multiple forked processes), the 3.4 branch still provides the stable branch.
Some changes to how route are announced will continue during the early 4.x release cycle until stabilisation but unless really required no backward incompatible change should happen.
This version is a python3 application with python2 support. Version 5.x will remove python2 support (but this is not expected soon).