I am confident in saying that DNM-37 has revitalised my puzzles and made it more fun and easier to practice for longer. I definitely prefer this to Aqua and it turns slightly slow puzzles, like my RS3M 2020 and RS3 Pyraminx, into just the right speed. However, I have noticed that it is better in puzzles that have already had some lube before. My 4x4, for example, is quite new, and the effect of DNM on that was less desirable, making it less easy to turn the layers I wanted to (the two outer layers have more friction for some reason). However, in general, I would recommend DNM-37 for all puzzles (not just NxNs) - just don't expect some sort of magical effect that immediately and invariably makes you or the puzzles better! Although I didn't think so before, controllability and feel are big factors in a good lube as well.