Thanks for the reply that's really informative. I have been looking at a couple of i40's and also a Golf (my other half has a Golf) before I bought the i30. I would completely agree that, kit wise, the i30 blows the socks off most of its contemporaries but I'd say that the Golf is miles ahead in terms of the drive and cabin refinement.
The noise from the i30 came as a surprise to be honest as it wasn't something I picked up test driving it. I came out of a Passat to get into the i30 and the VW is renowned as a super quiet car so maybe i am making an unfair comparison to begin with. However the noise, especially at speed, from the i30 is something I find intrusive and I am not sure there's a lot I can do about it.
I am going to look at a couple of i40's today and hopefully get chance to have a whizz about in one. I am also after an auto so will see what they are like.