Hi mate, 
  
I have the DC cat back dual exhaust system...... not  the headers though. With just the exhaust, it sounds lovely! Really deep burble at low revs then a   proper bark at higher revs. Also not too boomy on motorways as my daily drive!  
  
I love it, not the best finished end pipes in the world, they are just round and big, but then again its not the most expensive system in the world either. 
  
I know when Evo had the headers on, they said the sound was fantastic..... not sure you need them though, you not going to get a massive performance increase etc....  
  
Anyway, lots of the other guys have heard it on the drive out, so sure there will be some other comments......