Old D/A chips have the advantage of using ladder and NOS technology, but the disadvantage of not supporting hi-res and not dealing with HF transients very well. They can sound very musical, but not quite live from top to bottom IMO.
New D/A chips are much faster and support hi-res, but they are more difficult to deliver power to. The designer must have a very good bag of tricks to make them sing. The issues are: power supply, decoupling, ground-planes, wiring, and most important: regulation. Implementation is everything in a DAC. Its not just about selecting the right D/A chip and doing a design with it. The thing that sets most audiophile electronics apart from mid-fi is excellent power delivery. Read lots of professional reviews and try to make a choice using these. I personally trust Audiostream and usually 6-moons among others.
Steve N.
Empirical Audio