Well, one thing that can be learned from a bugstorm is the value of a test first development model :-)
People test first before deployment? And there was me thinking my QA dept were just a like any other group of screaming users! Silly me - my QA dept and ${GROUP} screaming users are one and the same. Seriously now, Big Ball of Mud is such a familiar pattern by now that maintainers either take the "Don't touch - it will break" or "Fix it - fair means or foul" approach. I commend the later, even if sometimes foul means == bugstorm.
the only bad experience is the one you've learned nothing from