ngarnier
commented
6 years ago mj-raw will basically allow you to add any content anywhere (for example between sections), whereas you're limited by the syntax with mj-text (as your content has to been inside a text tag, which is inside a section and a column).
However, if your plan is simply to add custom HTML to have more control on your layout than with MJML tags, mj-text will do the job perfectly. mj-raw will be more useful to use a templating language for example as you can put it anywhere.
This should answer your question so I'm closing, but feel free to comment if it's still unclear.
I am currently using the grapejs editor with the MJML framework. I created a block (within grapejs) to insert raw html within a template. It works best with mj-text. Is there issues later I can run into with mj-text? I know that mj-raw is made for this purpose but it interferes with the drag and drop of the grapejs editor.