the question doesn't make sense as you and I have no way to judge a sound from your friend's word.
Using a digital output, any kind, implies the use of a subsequent D/A converter device, which we don't know about. Your friend didn't say which converter has he used.
….so we are left with not much…
We can only say that the Eclipse digital output "may" sound better than the internal A/D converters if the unit is connected to a better quality than the internal conversion…but again, we would be judging only the conversion, NOT the Eclipse digital out.