TeamCity 8.0.4 (build 27616) is released which contains lots of fixes on top of previous 8.0.x release. These include performance improvements and several important fixes affecting many installations. Update is highly recommended.
This version uses the same data format as all the other 8.0.x releases, so you can downgrade within these versions. Get the fresh release at the download page.
Our development effort is already focused on the forthcoming 8.1 release (due in several months). There will probably be more 8.0.x updates, but those will only include critical fixes and will be released when/if the issues are discovered.
P.S. I've just returned form JavaOne event in San Francisco where we have enjoyed many conversations with current and future TeamCity users. Thank you for stopping by JetBrains booth and appreciation of our tools!