The driver's seat feels nice and comfy, even after two or three hours of driving. Not too much pressure under the legs by the knees, and not too little lumbar support. I imagine the passenger's seat is the same, but I so infrequently sit there I can't really comment.
see full Nissan Frontier review
I only rode in the back a couple times. Keep in mind, this is not a full-sized truck.
The legroom isn't much, but sufficient for a smaller adult or, if you keep the trip short, most anyone. The seat isn't really wide enough to comfortably sit 3.
Also the seating position is very upright - like church pew upright. I was not a fan, but I never sit back there anyway. :)
see full Nissan Frontier review
What Our Members Are Saying about the Seat Room and Comfort of the 2014 Subaru Impreza / WRX
2014 Subaru Impreza / WRX Seat Room and Comfort: Cons
The lumbar support is slightly lacking for me, but I have dancer-like posture so it could just be my preference.
The seats are very plush and well-designed otherwise... go sit in one.
see full Subaru Impreza / WRX review