Building distributed embedded systems from scratch is not cost-effective. Instead, designing and building these systems by using domain specific components has promise. However, in using components, the most difficult issues are ensuring that hidden dependencies won't cause failures and that non-functional properties such as real-time performance are being met. We have built the VEST toolkit whose aim is to provide a rich set of dependency checks based on the concept of aspects to support distributed embedded system development via components. We describe the toolkit and its novelty. We also use VEST on two case studies of a CORBA-based middleware for avionics. Data collected shows that VEST can significantly reduce the time it takes to build a distributed real-time embedded system by over 50%. Key "lessons learned" from our experience with using VEST on these case studies are also highlighted.