Initial thoughts...
I tend to lean towards liking the prose approach as a GM, whether that's boxed text in a pre-made adventure or prose that I have written up/improv 'd myself. It allows me a chance to create atmosphere while also allowing (when pre-written) the chance to make sure I haven't missed anything important. As a player for me it's just more evocative and immersive than the conversational narration, and draws me in more to the imaginary world the group is a part of. That said I want to make it clear that good prose doesn't have to be lengthy or overly descriptive, good prose IMO uses just enough word count to set the mood, evoke emotions and relay necessary information and err'ing on the side of shorter is probably better.
I have played in conversationally narrated games and it tends to create a sense of being a further step removed from my character, not sure why. I also noticed that it tends to increase side conversations, jokes, etc that can at times shatter or break the mood of the game There are also instances where it devolves into a million and one questions, many of which would/should have been answered if an actual narration had taken place and tend to (the longer they go on) pull me out of my character as well.
Now that said I don't expect the GM to keep up that level of description or narration for everything in the game, but I enjoy it as a scene setter an introduction to important and new things in the game and as a way to initially set the atmosphere, tone, etc of the game. I have no problem with the conversational narration if it's covering something like quick travel, an unimportant room or even nameless pointless NPC #237.