PHP 7.2 is soon to be released
PHP has matured rapidly the last 2 years and since the quite revolutionary 7 series started. PHP 7.0 did a lot for speed with its new code for memory usage and performance. We run a number of Joomla CMS website and we noticed quite significant performance boost on all of them.
PHP 7.1 and PHP 7.2 continues to give us some new features and enhancements.