I have no idea of the difference(s) in performance between wlroots and Gnome's compositor. Protocols do not have performance, implementations do. If someone can prove that the Wayland protocol, on a certain set of tasks, and in a certain environment, has a better or worse performance than the X11 protocol, then it might be possible to make abstract comparisons on protocol.
Given that Gnome runs on both X and Wayland, it might be interesting to hear from the Gnome authors on the performance differences.
Given that Gnome runs on both X and Wayland, it might be interesting to hear from the Gnome authors on the performance differences.