Phalcon is execution performance. I looked at my experience with Phalcon 3 and thought about what I would change for performance and easier development to use that performance.
The router slows down fast due to regular expression type processing. For a future performance enhancement, I would look at an intermediate router with no regular expressions. Match the request path then pass the remains to the target code. Start at the top of the list with the longest path definitions.
For easier development, I think the documentation needs something between the basic code definition and the example application. I had to look through the Zephir code to find some of the odd bits. Is there a process for taking questions in the forums and converting the answers to examples in the documentation?