You really can’t get away from it: DDN reads like an iteration of 3rd Edition. So for DDN to really work, it needs to keep everything that I liked about 3E, of which there’s a lot, and trash the stuff that put me off the game and eventually made me such a willing supplicant at the altar of 4E, of which there’s also a lot.
The Good - There's a lot of stuff I loved about 3E. It's difficult to separate the actual qualities of the game from the surge of excitement and relief that came from knowing D&D was finally in experienced, enthusiastic hands and that the product they were turning out was of such high quality, but after playing it for so many years I think I can scratch up some objectivity.
Unified rules - I vividly remember sitting on the sofa reading the 3E PHB and wondering where all the stuff I knew from AD&D2e had gone. It took a tangible mental shift for me to grok what the designers of 3E had actually done and how it all fit together into more than just a jumble of systems that, in previous versions, had happened to work well as a game (or didn't, as the case may have been). If I ever have to reference a table to resolve a die roll, the game has failed in this respect. For a good, free-flowing session where the DM can adjudicate fairly and improvise smart rulings on the fly, the mechanics need to be intuitive and broadly applicable to a wide range of play.