Hello,
If you really ONLY listen to soundquality and let all other points out, i would go for the AK240, if you can get them for the same price. I feel (and this is all heavily personal) the AK has more clarity, more structured and more defined sound. (All thise judgements are always in a very very minimal range and most of my friends tell they can hardly hear differences when comparing such devices
Even DX160 has a incredible Price/Prformance ratio. (One need to consider the price of a new AK240 at the time it came out and the price of the DX160 now..