The Milltek sounds different to the OEM exhaust - it's a matter of opinion whether it is better. I think it is.
However, if you add in High Flow Cats and maybe a JWT Pop Charger as well......now you've got a proper noise The advantage being that when you give it the beans it makes a great sound but when you are on lower throttle openings or on the motorway it's not droning away. The perfect solution as far as I'm concerned.
(PS. you should have an Uprev re-map if you have the above done - particularly the HFCs)