i guess we will have to agree to disagree seth. i've been using both mantis and bugzilla for about as long as both have existed, and i simply find bugzilla very cumbersome to use -- and i'm not the only one with this opinion of bugzilla. it is very common. surely it's not some huge secret conspiracy by the illuminati to defame bugzilla... is it? :)
i find mantis' interface streamlined in comparison, especially when juggling lots of bugs simultaneously. to you it's objections about eyecandy. well, you can edit mantis' css to make it equally an eyesore as bugzilla -- but why?
to me it's about efficiency and usability.
as for security issues -- both bugzilla and mantis have had vulnerabilities. bugzilla is not an automatic win simply because it's not php.
-Dan