I've never heard either, so I'm afraid I'll have to rely on the opinions of people who's taste I trust, at least at first anyway.
But I'm leaning toward the iBasso to begin with, being a big Android fan.
But I tend to agree with the opinion of many others here, that if the AK100 needs to be modded to simply be acceptable, that makes it a (far) inferior product.
But in the end, it's stellar sound that I'm after, so if, IF, the RWAK100 does best the DX100 I'll have to seriously consider my options.
And I guess we'll all have to wait and see just what HiFiMan ends up releasing...
AnakChan will have both in hand (DX100 and RAW AK100). I'll trust his opinion over many for that matter :).