Man I wanna get into it, but I'd feel so guilty reading it before TOG. I get TOG recommended to me almost everyday lol
Imo ToG excels in its wide lore. Its ambitious to be like OP in the wide lore but in manhwa world. But, the author-artist seemed to exhaust his ideas already in earlier chapters, so since the arc of "some train floating in the air", i feel like it recycles the same trope of "having to participate in some kind of game that culminates in fighting a strong enemy, in order to clear the floor" stuff, and the lore kind of just disappears into shenanigans that support the "game/mission at each floor", instead of the other way around.
Imo it significantly dragged since the "flying train" arc. Each game and fight become longer but the art become more and more focused on just energy beam variations filling the entire screen, without proper emotion-building, interaction, pay-off in the end of each arcs.
While Gosu is completed, just 200 chapters or so. It drags in the last arc and it becomes full-blown shonen powerlevel explosion in the last fight...but imo its due to the author is really sick so he cant explore the storytelling beauty unlike in the earlier and middle chapters. Author had lymphoma stuff, but still completed his story. It finished satisfactorily, it doesnt overstay its welcome and it finishes without any questions left.