A C++ ACE Framework developer is a valuable addition to your team because they can seamlessly handle high-performance network programming tasks. They have a deep understanding of the ACE (Adaptive Communication Environment) Framework, which enables efficient development of distributed, real-time and concurrent software systems. Their expertise can help in reducing system bottlenecks, improving code modularity and reusability, and ensuring stability and scalability of your software. They are skilled in managing complexities associated with operating systems and network programming, making them crucial for robust, high-performance software development.