Which Nakamichi to choose?

If both are in the same condition, the best choice would be the Cassettedeck 1. The DR-2 is newer, however the Deck 1 has the better transport. The Deck 1 has, what some techs call, the basic Dragon transport. It is cast metal and the DR-2's transport is stamped metal. Also, the Deck 1 has real time monitoring, not a feature on the DR-2. Here's a link for more info.

http://www.naks.com/

"Practical difference between cast and stamped metal has probably evened out over the last 25 years. If they have survived, they have proven reliable enough, I would say."

Both transports were reliable. It’s just that the cast metal transport sounded better and it always will.

Either deck would likely give you good service, but as I previously said, as long as both decks are in the same condition, the better choice is the Cassettedeck 1.

It's true that the many cassette decks suffered high frequency loss using Dolby Noise Reduction, however this was not an issue with the better Naks. I have owned a Dragon, CR-7a, 670ZX with NR-200 Dolby unit, RX-303, 581Z, and still have my original 582. None had a high frequency loss using Dolby.

lowrider57, don’t remember how to describe it, but Dolby C just never seem to sound exactly right, so never used it.

The CR-7a is an extremely nice deck, however not one of my favorites. It is a later model that used the stamped metal transport. The higher end models using the cast metal transport always seem to be just slightly better. A couple that I lusted after were the ZX-9 and the 682ZX. A certified Nak tech I know thinks the 682ZX was as good as anything they ever made.