Developers of software engineering tools are facing high expectations regarding capabilities and usability. Users expect tools tailored to their specific needs and integrated in their working environment. This increases tools' complexity and complicates their customization and deployment despite available mechanisms for adaptability and extensibility. A main challenge lies in understanding and managing the dependencies between different technical mechanisms for realizing tool variability. We report on industrial experiences of applying a model-based and tool-supported product line approach for the customization and deployment of two Eclipse-based tools. We illustrate challenges of customizing these tools to different development contexts: In the first case study we developed variability models of a product line tool suite used by an industry partner and utilized these models for tool customization and deployment. In the second case study we applied the same approach to a maintenance and setup tool of our industry partner. Our experiences suggest to design software tools as product lines; to formally describe the tools' variability in models; and to provide end-user capabilities for customizing and deploying the tools.