In my experience, D5 Render is remarkably stable, even during very long, multi-hour modeling and rendering sessions.
Since it is built on modern architecture and optimized for real-time performance, crashes are exceptionally rare. I find that I can work consistently, making numerous live adjustments to lighting, materials, and composition without the program suddenly failing.
The stability is a huge advantage for professional work, as it allows you to maintain focus and not worry about losing hours of progress. It performs reliably throughout the entire workflow, from initial setup to final rendering