Actually it is hard to tell if I2S is actually superior for there are very few devices for sale that go directly into an I2S connection--that is other than those that convert either spdif or USB to I2S. A quality DAC should already have quality spdif and USB inputs with the conversion to I2S done internally.
Some DAC I2S connections use ethernet connectors; some use HDMI cables. Mine uses both. The ethernet cables are fairly easy for an amateur to alter to meet I2S needs. Some units that feed into I2S have a bunch of dip switches so that no specially made up HDMI cable is necessary.
But I2S, which is how a DAC communicates internally, has never been much use to audiophiles as there are very few units that feed directly into it--the reason being that there are so few DACs with an I2S input. There are some bridges feeding I2S that are relatively expensive and one reasonably priced that is not a terribly high performer. So all the R&D goes into those feeding USB or spdif.
So theoretically yes, but in practice no.
