Bug tracking and TFS?

Question

Hello, I would like to ask you about using Team foundation Server as bug tracking system. Already we are using Countersoft Gemini, this is one of many bug tracking application. Because we started to use repository and build from Team Foundation Server, we consider also migrating bug tracking system to TFS work items. What do you think about this? Can TFS be utilized as complete bug tracking system with time logging and issue managements functionality? Do you have any experiences with migration from other bug tracker to TFS? Thanks for answers cyberjoe