Yes, the difference apparently is not that visible but what gurus say is that less expensive mass produced components were used.
However, if you open up the DR and look it up, the work inside is just as good, if not better than any other previous NAK models. Of all the DR models, the DR1 (3-head) and DR-3 (2-head) were considered to be the best (and also are the more expensive ones on the pre-used market). There are lot of conflicting opinions but there is a school of thought that suggests that the DR3 was perhaps one of the best ever 2-head decks from the NAK stable, if not the best. It had a mix of contemporary technology of the times blended with a great design and a very high quality build. But all this is stuff which I have read online and is debatable. I have thoroughly enjoyed my DR3. On Sunday this week, I took it to our local Church and recorded the Church service for 45 minutes, with a line output, direct from the Harman 12 channel mixer. I have never heard a home made live recording sound so good. Simply brilliant!!