I'm not into handheld gaming at all, but if devs are allowed to use it as a secondary screen, GT7 HUD in your hands instead of on the tv, I could be persuaded. (Well not with GT7 as I rather play that in VR). However it has no touch screen capability? So not even useful for inventory management... (If it was possible to act as a second screen)
Anyway, I miss the WiiU gamepad, this doesn't look like it will offer anything like it.