performance: apps are running on a subset of XOrg and xWayland translates it to Wayland
RAM: if you have no XWayland apps anymore you save RAM
features: some apps may have more features on XOrg, some may have more on Wayland. OBS on XWayland can record keystrokes, QGis on XWayland has not broken dockable toolbars.
Is there a noticeable benefit to those apps running natively on Wayland vs running through xWayland?
I have not checked this, but as far as I know