版本控制与错误跟踪软件集成的重要性

Currently we use FogBugz for tracking issues and found it to be ok. I'm looking for something else that can allow end users the ability to track their cases along with us. And something that actually works well with email. I've found a few alternatives that support those features but they don't integrate with version control. We've got all the SVN hooks in fog bugz and we use them - but I haven't really found them all that useful. Has anyone found a really good reason to need version control integration with the bug trackers?Currently we use FogBugz for tracking issues an