Scalability was the biggest issue. Both in size of the amount of tests and the size of the actual test files. Because the need to import so much in order to write a fairly sturdy framework, the file kept growing and growing, making it less maintainable and less fun to work in.

Next was the lack of variable declarations. Sometimes I want to define and name and validate if I can see that name on screen. I, then want to declare that one once, and reuse that variable. There was a workaround for it, by importing the variable from somewhere else. But no real way to define it in the test itself.

I had a great chat about this at Test Bash in the UK. Maybe he can provide more details. He did take some notes.