I only take out the rear seats when I'm gutting the car for any serious racing. The rear seats are pretty light as is. The only real weight that is a lot easier to remove is the spare tire.
I think the seat deletes make it look homemade or unfinished. For some reason, it reminds me of back in the day when guys used to make homemade speaker boxes and they took up the whole rear of the car. Wood that looked like it was cut with a handsaw and caulking all over the place.

 

Rear seat bottom is so light that it is no problem removing. Use a screw driver to pop their release at two points roughly 5 inches in from bot sides. Backs need unbolted from their retaining hardware.