To the person asking about the HTC One X DAC - which version of the One X are you talking about?
The DAC isn't known for any of them, but I have the international One X and the sound quality is bloody average. The AT&T One X uses the Krait S4 and it's likely to have better sound quality than the international One X going by the the audio quality of the One S which also uses the Krait (GSMarena have RMAA recordings for both, FWIW). Even that is very likely going to be inferior to the S3, especially once Supercurio releases Voodoo Sound for it. If sound is the key differentiator for you then the choice is very likely going to be straightforward, although as others have said it'll be a while before we know for sure.
In relation to TouchWiz, as others have said, just replace it with a launcher from the Market, I use Nova myself (Apex is good too). I've never understood why people factor in the stock UI so strongly in their phone buying decisions when it comes to Android phones when you can just change it.