I just put on the invidia N1 street dual exhaust last week. I like it a lot. I have a 2011 STi hatch as well.
I also put a catted cobb DP on and a grimmspeed ebcs and had it tuned. Car is amazing now.
I had the invidia cat back on for a few days before I added the DP and the tune, the invidia alone was very deep sounding, the DP made it a bit more throaty, but still very deep rumble.
I was looking at the nameless CBE but it was quite a bit more. The invidia CBE was 680 or so from rally sport direct.