One S has comparatively better display. It competes with Droid Razr. N only trained eyes can notice a different. Dont complain Pentile display,we are used to use that.
But if you ever held a Moto Atrix2,you'll notice a diff cuz its non-pentile.
Single Thread performance goes to One S.
Multi-Thread performance goes to One X with Tegra 3. So it depends what else you want from smartphone. If you are so much into gaming the Tegra3 will be fine but Adreno 225 is currently the best GPU after ULP GeForce. N there is no benchmark tree that can record the whole 12 Core GPU performance of Tegra 3 so its still the best.