Sorry, I just saw this message by chance.
since you're in South Korea I guess you had opportunity to hear a couple of Jun Bl catback exhaust.
=>Yes.
How would you compare Jun Bl's Gt and racing catback exhaust?
=> I had the JunBL GT on my car, but I don't think I have ever heard the Racing other than in video. I liked the sound of the GT version but it had a bit of drone from 1800 to 2200rpm, which was annoying when passing someone while cruising on the highway. (mild acceleration at cruising speeds)
I want a catback that gives me that roar when I floor it, but I don't want it to be annoying while cruising. Yet I don't want to spend 2000 bucks and then be desapointed by how quiet the exhaust is.
=> Almost all exhausts have a bit of drone at cruising RPMs. The only exhaust that has none was the RES titanium EVC exhaust, that I kept for 4 months or so. No drone, but the sound was not pretty so I finally got rid of it. (3500bucks...)
Jun Bl's build quality seems to be way higher than Borla's.
=> I can't comment on that, but in Korea there seem to be a consensus on the fact that the best sounding exhaust is Borla.