It is stable while also being a great product.

From my experience of using this solution, I have found ColdFusion to be very stable.

I would rate the product's stability a nine out of ten.

None.

With larger applications I had issues.

Anything that I might have found over my years as a ColdFusion instructor and software architect was due to bad code or bad practices. Some issues were easily fixed with the help of Adobe ColdFusion enterprise support, which was expensive, but worth every dollar.