My Arqray Twin developed a rattle just after it's 1 year warranty period -- seems like a weld on the interior baffling had broken (but not sure, just something was rattling around in there). I'm now using a Larini 8". The Arqray Twin sounds nice, but is on the loud side -- I had to use ear plugs when driving from NorCal to SoCal (5 hours) with Arqray Twin + Cat + stock header. But doing the same trip with Larini 8" + no Cat + Weapon R header did NOT require ear plugs.
I'm going to consider muffler replacement a yearly purchase/service item -- all of them seem to degrade pretty quickly and the more one tracks the car the sooner they degrade.
I think Phil (TurboPhil) has some cans that one can actually re-pack (serviceable) -- this is probably the direction I'll eventually go once I burn thru my Larini 8". I think it was carbon fiber can, but don't recall if it was a rivet or threaded for servicing -- rivets aren't a big deal, just drill them out.
It's hard to get any 4 banger to really sound good IMHO. V8, V10, V12 etc. etc. they stir my soul - but 4 and 6 bangers do nothing for me in the singing engine department
Rob.