A bit off topic, but im reading a lot of older Manga right now like Phoenix by Tezuka, The Drifting Classroom by Umezu and Ashitae no Joe (they are all hardly recommended by the way). And one thing that immediately springs to the eye, is how slow paced they are. Well, slow paced compared to the age of Manga we are in right now. For example, in Ashitae no Joe, the main character doesn't start boxing till the third volume. That might sound like its too slow but actually, it's really perfect. We get to know the main characters, the setting by a nice tempo.
The counter part to that would be, Manga like Undead Unluck which changes its setting almost every chapter. My theory is that Jump changed the pacing of Manga forever. With the introduction of questionnaire cards, Manga already had to appeal to its readers by the first chapter. Its do or die. I think that's also why a lot of first chapters are structured too similar nowadays. A lot of them are predictable and you can already guess after reading the first page how the first chapter is going to end.
I feel like Sunday, even if im not a fan of their line up for the most, are the only ones that let Manga breathe nowadays. Recently, there was a Komi chapter of Komi just being hungry at night and making some food. It was pointless for the story and didnt contribute to anything but it was nice to see a character just doing normal fun things. That chapter is something that could only run there and wouldn't fly here Jump or even Magazine.
This might be just a lot of rambling in the end. But wanted to get it out.