a) It . is . so . incredible . very . slow, it . takes . 7 . seconds . to . load . a . page . when . hosted . on . atlassian.
b) Search is bad. It might be possible to find issues I have commented on 1-2 years ago and I have commented on and which contains some text, but the interface and results are no where near as good as a simple text search in Mail.app. This makes Jira a black hole where everything disappears into and is never heard from again.