In this paper, we report on our 5-year's practical experience of designing, developing and then deploying a Model-based Requirements Engineering (MBRE) approach and language in the context of three different large European collaborative projects providing complex software solutions. Based on data collected both during projects execution and via a survey realized afterwards, we intend to show that such an approach can bring interesting benefits in terms of scalability (e.g., large number of handled requirements), heterogeneity (e.g., partners with different types of RE background), traceability (e.g. from the requirements to the software components), automation (e.g., requirement documentation generation), usefulness or usability. To illustrate our contribution, we exemplify the application of our MBRE approach and language with concrete elements coming from one of these European research projects. We also discuss further the general benefits and current limitations of using this MBRE approach and corresponding language.