There needs to be a points system along sound, reliability, head durability, other part availability, tech availability, belt availability, recording quality, playback quality; for recordings, compatibility with other decks; last for me looks (different categories for chrome vs plastic vs meters plus size). Also layout and ease of use for recordings; can you use Metal tapes and calibrate to different tapes easily.
Also people who give ratings should clarify what equipment they use: what amp and speakers. Is it in the living room or a dedicated sound room. If you use headphones, is it via the inbuilt headphone amp vs line out and separate headphone amp.
I had an OCD crisis because an overhauled BX300 had rhythmic static noise in the headphone signal, which we pinned down to the cheap replacement motor for the original one that develops a dead spot. So I hunted down another original motor from a Yamaha deck, and a friend replaced it for me. If I had used the line out, probably would not have bothered. If I had not used headphones at all, probably would not have noticed. But now when someone says BX300, I cringe. If your tech knows how to rebuild the original motor, maybe no longer an issue. Then also the bias pot that breaks and the replacements don’t have a middle point. Then also the issues with poor meters and the controversial sliders for recording. Good non-slipping idlers are hard to find. Overall, great playback machine but with shortcomings that now put it off my list. Yet some people have used it as a reference recording deck.
RX 505? Awesome deck but there is only one good belt source in the States, otherwise your w&f shoots >0.10%. My JVC m70 boombox has better w&f than this.
Dragon? Ok but make sure its serial is between 20,000 and 30,000 and make sure it’s had little use

if It’s <8000 good luck finding a tech.
For me I listen via a boombox (a good one like the JVC PC 55 or Panasonic DT8) in a room with a poor placement of the sound source, to my side; or via headphones, and often on walkmans, so I value universal recorders that are reliable.
So it’s like cars indeed, a Ferrari is awesome as a toy but for a farm where I want to carry hay or tools, I’d rather have a pick-up truck for daily use. There needs to be a point system, with real-world constraints around maintenance today.
I actually worry most of all about two things: belts and techs. Both require the skills of people who learned decks in the last century and are getting older now. Maybe younger people will pick up these skills, who knows. They are being made lazy by mechanics-free music that you don’t even needs hands to play.
If you want to get a holy grail, make sure you have a plan how to keep it running.