What model do you have/talking about?
They aren't discontinued and still readily available.
08+wrx 5 doors have two different styles. 08-10 single exit, 11+ have quad tip dual exit.
All 08+ sti spt sedans and 5 doors should be the same through the years.
My guess is the price, stainless steel quality, sound, and pipe diameter all come in to play here. For a near 1k msrp you can get a far better exhaust for your money. The only pros are warranty related for people that would be nervous about running non factory performance parts. And a pretty quiet but sporty sound in my opinion. I run one and love it. It fits my needs and power goals just fine and would recommend one to someone else.