In my opinion, with proper know how and the correct set of tools and test tapes fixing a 3 head machine is not more difficult than any other decks. Especially naks. Their transports are way more simpler than the usual auto reverse transports found in denon, Sony etc. In naks, the 3 head models have many more features and the playback and recording performance speks are way better than 2 head models. So the difference is not just real time tape monitoring. I have a dragon, CR7, CR3 and dr3. All of them work perfectly. They just need to be taken care that's all. As for parts, belts are available. But takes time to come from abroad. The rest of the parts are anyway rare for tape decks nowadays. So if one has the opportunity, my suggestion is to go for a 3 head deck and enjoy it.