USB to i2s please, which sounds best?

Radian: looks good from outside, but there nobody knows what is inside. Also, good sound is subjective...you need to elaborate.

In any case, i just ordered a JLsound unit, which seems decent at least and hopefully more than that.
 
I would also leave a link to thread of my USB transport York 🙂
 
I2S can actually make a difference. E.g. if timings (setup and hold times) between I2S signals are not as DAC expects there will be "dropouts" or no sound at all. Another possible cause for audible differences is noise carried over to DAC via I2S connection.