Screen-resolution: Rift/Vive vs GearVR

How would you evaluate the immersion quality of these devices displays?

I wonder how the OculusRift or the HTC Vive (both 2160x1200px) could be "better" than the GearVR with its 2.560 x 1.440 pixels (Galaxy S6 PenTileMatrix).

I know the resulting quality depends on more than the resolution (Lenses, FOV, Refreshrate, DisplayMatrix-Type,...).