Whichever is most suitable for transitions, exposition, or moving the plot along.
Either can accomplish what I had mentioned.
I found that readers tend to see overly descriptive sections of my own work to be less immersive, so I've changed things in my newer chapters to have my MC deliver some of the exposition or explanations so that it 'feels' more fluid and immersive when read.
I tend to read my own work as-if reading any other book when I perform my final edit before publishing, so I do agree with the criticism.
Of course, this immersion aspect is only really a problem when writing in 3rd person.