I would also recommend going with the T2 over the D2 if it is within your budget. There is a very large improvement in sound quality, unless the specific character of the D2 is more to your personal liking.
Lumin has an outstanding software stack and wide range of compatibility which makes it easier and more pleasing to use than many other choices. Plus they their build and sound quality is top-notch, and they have a high level of customer support and regular firmware updates to improve things.
Most R2R DACs tend to lean towards a particular flavor of sound, so unless you've heard one yourself and decided you liked it, I wouldn't necessarily recommend it.