Earlier quoted context omitted.
Confluence is the wiki we use where I work and I absolutely hate it (ending tags is like you are opening a tag, so {bold}this would be bold{bold} (example, I don't remember any tags off the top of my head). If something better came along that helped us rather than slowed us down it would be fantastic.
Oh god. I helped support an overly customized Confluence wiki that was to be THE wiki for the entire company one summer. I quickly grew to hate the software quite strongly. Took me a while to be objective about JIRA's other products when I used them later.
JIRA is absolutely terrible as well. I can't express in words how much I hate and dislike JIRA, it's horribly slow and bloated user interface and how complicated it makes certain tasks... using it as an Agile tool makes it even worse especially with Greenhopper the add-on.