I was a DIVI lover and used to recommend it in my community all the time believing it like as if it was the best thing one could expect at a price of just $200 (now 249) for lifetime, until I met Oxygen Page Builder. It was a great deal given the big community and lots of supported third party plugin, worthy mention plugin from TORTOISE IT - Like the Woo Layout Injector and the DIVI layout injector. So why did I still switch read my whole blog and you will understand.
First thing to clear is the reason for me getting DIVI:
but it was not enough for my projects such as a listing site.
Divi overall is great but the need for third party paid plugins would always get on my nerve even if they were cheap when I bought it. Compared to Oxygen this is different they give you the power to do everything yourself giving it just the right amount of nuclear power to become the best.
when it comes to comparing bloat i always felt DIVI to be bloated with features like for example the contact form. I usually end up using CF7 or Fluent Forms this are by far the smallest contact form and end up giving almost zero load time impact. Another example would be the unneeded CSS codes that are there in DIVI even if you are not using that particular module. Oxygen on this regard is bare bone thus making it by far more lucrative. Below is a chart for comparison:
As Oxygen has less scripts and CSS, it is way faster than any other builder I have seen also the method it uses to deliver output is on par with the current trends.
Oxygen has many features some core to oxygen only. One such feature is the conditions for all elements. Conditions is like sprinkles on top of elements, it can range from cookie based condition to interaction based condition. For example for a E-Commerce homepage one can set elements based on the time and day of the month. They can also set if in mobile show some thing else show blank. Such features are available in other builders too but they are limited, limited by the fact that the code output will happen but would not be displayed where as in Oxygen the code is not even produced so less codes for the browser to process. This helps to speed up sites that are big such as E-Commerce or Listing sites with ever changing contents based on user needs and interactions.
If some is starting with page builders Divi would be a great place to start if you want all in one item but if you are a novice at wordpress oxygen would be the best option there is.