Gusterón is a playful, colloquial augmentative of 'gusto' (pleasure or taste), used to describe an especially great or intense enjoyment, bigger and more satisfying than an everyday pleasure.
In the song, the lyrics say "Tremendo gusterón comerlo to'" ("Tremendous pleasure to eat it all"), using gusterón to exaggerate just how enjoyable the experience is.
Cruz Cafuné and Leïti spend this song caught between two moods: living large and missing someone.
The verses paint a fast, wealthy lifestyle — riding in a Suburban LT, a sold-out merch line, a room at the Abama resort, seventy-band paydays. It is a victory lap, and the artist has no patience for the haters who will keep talking regardless.
But the song's real center is quieter. Twice the hook turns away from the flexing to something more fragile: save the chats and the videos, because if he dies tomorrow, he wants her to still be able to hear his voice. Underneath the bravado is someone thinking about mortality and holding on to a memory of a woman whose perfume still lingers on a pillow.