I own the single exhaust pipe Borla cat-back, not the hush. It is a little loud for my taste. If I had to do it over, I would buy the hush. I am unfamiliar with helix. Quality wise, it would be hard to beat Borla.
I had the same problem deciding because these were my two finalists also. I was leaning to Borla because of who the company is untill i went in to the "hang out" section and clicked on the 100 megabites of wrx videos(scroll all the way down to exhaust) and heard what the Helix TBE sounds like. I fell in love with as soon as i heard it. Its a black wrx pulling out of its garage and then he goes on a little ride. Like i said before its ## car, go with what u want to, but check out that video, its sounds awesome
I am running a Helix downpipe and Helix catback. I don't like the look of the huge angled muffler out the back of the car, but for $400 of the TBE I can't complain much. If I was to buy another catback it would probably be the Perrin.
if you want good flow but not a lot of sound its not a bad move. not to mention it keeps the eyes of cops off your exhaust.. i have a big fart can and i want something a little more lowpro so im looking at cobb, they have a good sound and very nice look.