I have a full sports Milltek system which is resonated, one day whilst my car was in for a lower engine mount upgrade I was asked if I would like to try a non-resonated pipe I said yeah why not

within 24hrs I was back at the garage having my resonated put back on

It drove me mad

I must admit it did have a louder note to it , but it was soooo noisy and droamy inside the car that I couldn't put up with it.
The resonated has a sweet tone and is hell of a lot quieter in the cabin, saying that its everyone's choice at the end of the day!