We have used Agiloft for many years for tracking bugs, enhancement requests, and other issues on our software and consulting projects. We have also used to to create a sophisticated online tool to find and share energy data called Megajoule.org.
It is ideal for managing a wide range of business processes from CRM to technical support. We use it for issue tracking and technical support. We also used it to create a highly structured knowledgebase with contributor content. It might be less appropriate for detailed quantitative modeling.