The author of this text has been using Test-Driven Development and PHPUnit for a long time, but recently discovered PEST, a new testing framework that could potentially replace PHPUnit as the de-facto tool of choice for writing TDD PHP. The author tested PEST on their own Vonage PHP SDK project, which already had a comprehensive test suite, to see how it would run and compare its performance to PHPUnit. PEST is backwards compatible with PHPUnit and has a similar syntax, making it an attractive option for developers who want to adopt a more functional programming style. However, the author found that using the Pest Converter tool, which aims to automatically convert PHPUnit suites to PEST, was not smooth sailing due to edge cases in the Vonage PHP SDK project. The author concludes that while PEST is an attractive option, it's essential to fix any complex or over-engineered test suites before attempting automation with tools like the Pest Converter.