Great thread this ☺
And with some very well-constructed, well-reasoned points about 'vintage' versus 'modern' instruments that have really got me thinking.
Having thought about it, my 2p worth is this..
I'm kind of with Shaggy on this (as in his original post) in that I just enjoy the whole aesthetic of older, over-engineered instruments that look like they've been used a lot over time to make music with...
So, 'Bass Nirvana' for me is when I find an instrument that fits with how I like it to look, but also so that it fits with how I like it to feel and sound when I'm using it.
All three of those determining factors are completely subjective to me and are undermined by my poor hearing and tinnitus in my right ear, my lack of good (or proper) playing technique and my own quirky sense of what looks good and what doesn't.
Having said all that, one of my favourite basses that I really enjoy playing is a 5 year old Schecter Diamond P5 that doesn't look at all like my other basses, is way too big for me and will never gain any kind of classic status I expect. But I just love the way it plays in my hands and the sound I make when using it.
What's it worth? Probably about £300. Yet it's outlasted some much more expensive basses that I've had over the last 5 years.
I remember having a '66 Fender Jazz in the early nineties that I never really bonded with, much preferring an '80s Tokai Jazz Sound that I had for three years, which I then rather foolishly traded for a Music Man 5 string with a John East preamp that I never liked at all and which I sold on quite quickly...
Hence my conclusion is that I have no set perspective on this topic that I could reasonably offer to anyone that will be of any objective value, and that in the end, my preference for any particular bass I buy will be based on my mood and my finances at the time I'm buying it.
I doubt that all this will help move the debate along much though, but I'm looking forward to reading more comments as the debate continues. ☺