I think when you're talking about an instrument of this rarity and significance, terms like "playability", "tone", etc. are almost immaterial. This IS an investment, not unlike a work of art or any other valuable item you put on a wall or in a museum. It's what it represents as the birth of an iconic instrument compounded with it's background history that makes it important. The fact that you can plug it in and make music with it is a nice added bonus, but who in their right mind would drag it out to a local bar gig without a couple of armed bodyguards?
I understand being musicians we're passionate about elements of an instrument that make it play/sound outstanding, and it's quite possible this instrument doesn't possess any of those traits. But it really doesn't matter when you're talking about an item at this level anymore, and believe me, if you just plunked down $30,000 for it you're going to hear whatever you want to hear. It may as well be a rare stamp, comic book, coin, car, folk art (ever seen what some cigar indians or weather vanes go for?), etc. I don't need to be a painter to buy a painting.
It's a 1960 lefty Fender Jazz bass. I've seen only one other lefty (Route 66 Guitars years ago in sunburst). I don't care if an Alembic, Lakland, Custom Shop Fender, or a Dean plays better. They ain't a 1960 Fender Jazz Bass!