Greenshift plugin already includes GreenLight blocks and you can enable them in Greenshift – Welcome – Enable to show Professional blocks
There are few differences in GreenLight PRO plugin
Whitelabel
Unlike Greenshift plugin, GreenLight PRO doesn’t include branding and it’s whitelabel from the box
Query block and Slider
While blocks are very similar in both plugins, they use GreenLight local style panel and a bit simplified output
Woocommerce and SEO blocks
GreenLight doesn’t have such blocks and they are not in plans, however, it’s possible to use Element blocks and core woocommerce blocks to build e-commerce site or marketing blocks with GreenLight.
Performance
Both plugins are highly optimized. The Greenlight plugin can be a bit better, but the difference is so minimal that highly likely you will not see it.
You don’t need to buy GreenLight PRO if you have All in one plan in Greenshift. Just install Query and Animation addons to get all possible functionality.
You will need GreenLight PRO if you want to use ONLY GreenLight project and philosophy on your site.
More about differences between plugins and how to enable GreenLight Elements in Greenshift
Please note that the Greenshift license can’t be used for GreenLight PRO.