My Lexus GS300 has one. Very happy and sounds great...imo stick to "stock" when they ask how loud you want it, as even with there stock option, my Lexus is significantly louder than stock.
Over 3 years now. The left side did droop after a month, but they said this can happen due to the new metal going through heat cycles. I simply brought it back and they fixed it within 30 minutes, and it's been flawless since.
MIJ puts a lifetime warranty on there exhausts even if the car has a different owner, so if you have the receipt you can take it back and have it adjusted for free.