When PrestaHeroes says upgrade we include the whole enchilada. Not only will your shop have the latest PrestaShop admin features but more importantly a new shop tuned for 'best in class' visitors experience.
As a business owner you should always concentrate on running your business, and not technical details. If you're doing technical parts than who's running your business. there is literally nothing we couldn't make in Prestashop, starting from Front-end Changes, CSS, JS, Bootstrap, Module Changes, Module Creation.