In Redding terminology...
"Type-S Match" refers to the ability to use interchangeable bushings to tune your neck tension.
"Competition" usually refers to the seater.
So, you need both. And, Yes. They're worth it. But, you can get good results from other dies as well.
Next you need to decide if you want
(a) neck size only
(b) full length size only
(c) neck size plus body die for bumping shoulder
Option c gives you the most flexibility and control. But, depending on what you're trying to accomplish, you can get excellent results from FL or NK sizing.
For hunting/tactical, I lean towards FL sizing. And, for precision, I lean towards option C.
-- richard