Since 09/01/2016, 7 and PHP 7.1 are now considered stable and can provide an additional gain with opcache which is enabled by default, test and see the speed, but especially, check if one of your modules / plugins are not compatible with PHP 7 ....)
See :
https://support.yoorshop.hosting/knowledgebase/1100/PHP-versions-extensions-and-cache.html
For PHP 7 and 7.1, tick well PHP extension : mysqli and opcache if not the case, it works on most sites after...
Attention to ecommerce websites : make advanced testings including order process !