Release 0.8.10 includes two changes intended to reduce the number of router-to-router connections, and therefore improve tunnel build success rates and general reliability. Of course, there's also a few bug fixes and translation updates.
The 0.8.9 release has several performance improvements, and many changes to handle the continued rapid growth of the network. It uses a new iterative method for Kademlia network database lookups that should be more reliable and efficient. There are also several improvements to our SSU (UDP) transport protocol that should help reliability and efficiency. We have made several changes to improve tunnel build success rates. And, of course, there are lots of bug fixes and translation updates.