My problem with box text is that it never seems to suit the situation in the game.
I called this out in my initial post as the hardest part of writing boxed text. Invariably, even with boxed text, you have to improvise the wording to deal with unexpected perspectives. That's probably the reason behind Hickman's spare style. He's not writing out everything he's planning to say as a DM, he's just getting himself started with the key idea and he'll flesh it out according to the situation.
Even when there is a great description of the room, it always assumes a certain perspective that either reveals too much or too little to the players, so I always have to adjust the description on the fly. A great example of this is Klarg's Cave in the Lost mines of Phandelver. The description is from the perspective of the main entrance from the Twin Pools Cave. However, the characters could have scaled the fissure in the Kennel and entered through the chimney instead.
That's far an away the easy shift of perspective to deal with. The hardest to keep track of in your head and deal with when trying to describe something is the player's access to light. I find myself ignoring the player's light source 90% of the time just because different characters in the party would be able to see different details, and need to move to different places in the room to see the same things clearly. And are they using a lantern or dancing lights or a daylight spell at this point? I often find I need to work around this by going ahead and lighting rooms in the dungeon in some fashion, just to make the available light somewhat more stable.
Instead, I prefer to have the room described to me, the DM, to narrate my own description to suit the situation as it occurs naturally during the game. I like good descriptive writing then too. I will most likely be using the same phrases.
The key here for me is that whatever pattern is used to describe the room to the DM, has to be as organized and intuitive as boxed text. Gygax required you to skim his rooms for information you needed to convey, and no matter how many times you'd read the module it was way too easy to leave some important detail out and then have to put in an 'oh yeah, there is an X in the room' when the players start taking actions.
I do not like dialogue script written for me. The dialogue never seems to fit the situation in the game as my players never seem to ask "the magic question" and instead beat around the bush and come at information in weird angles. I do like sample dialogue to help shape the character -- catch phrases, typical statements, etc. While not necessary, it does help me keep from making all my character sound the same.
Dialogue script is hard, but I find it sometimes necessary. Generally speaking, even with a well prepared NPC, prepared dialogue is only about half of what you end up saying during the conversation, and like any prepared text you often have to adapt it to the changing perspective. But I get a lot of use out of it.
Finally, I will concede there is one bad point to boxed text, and that's loss of eye contact. Ideally, you could maintain eye contact with the audience as with any good public speaking. Boxed text is basically giving that up most of the time, at least at the start of the scene. But on the other hand, Gygax's rambling descriptions or bullet points are likely as anything else to break eye contact as the GM is forced to skim the information (often across huge blocks of text in a complex room), so it's relative disadvantage rather than an absolute one. Ideally of course, you familiarize yourself with the text that you need only glance at it to get the point across, but realistically that more preparation time than you could manage if it isn't your paid job.
