DAC Question: Delta-Sigma vs R2R

Those highly raved entry level DACs, including Topping E30, SMSL Sanskrit 10th Mk II and Loxjie D30, indeed have very good measurements and appealing to the ears. I had them all but sold them all after listening to mid-tier DACs such as SMSL SU-9 which is just in a different league with more dynamics, punchy low end and more engagement. Noise floor is also quieter. Not until you hear them side-by-side, you would probably never sense the differences. For example, among those entry-level DACs, E30 is the most neutral and analytical but leaner on the bass and tends to flat. This was also confirmed by one of popular reviewers on line, which means if I read more reviews and get more feedback before I pull the triggers I would potentially avoid so much hassle. I understand probably most of us do not have access to "trying" out as many as DACs or other gears within the neck of the woods. Take advantage of the "free-return" policy on Amazon, for example, but not to abuse it for being a good citizen. I would strongly suggest read as many on-line "reliable" reviews (use your judgement) as you could and narrow down to a few, say, 2-3 candidates, before trying them out.