The Page/Site Builders comparison is only updated every 6 months.
The two others are updated more frequently.
WordPress Page Builders comparison
What the most popular Page/Site Builders load by default in the frontend.
The Lowest the better (obviously).
WordPress form plugins comparison
This comparison will show you how much assets each plugin loads when you create a basic contact form.
A basic contact form should be light, easy to set up and his asset should only load on the page where the form is visible.
Oxygen Builder plugin features
A list of the most popular plugins for Oxygen.