you don't have to waste $4k, you could buy a basslab instead. that way, you don't waste your money, but get a bass that's really better in every sense.
no neck dive, no deadspots, no heavy weight on your shoulders, no changing neck warp.
and the sound is incredible rich, it has a lot of low frequencies, there is a nice crisp high register, and that growl that people sometimes call a "woody tone".
but unless you try one and experience what i mean, you will think that i'm one of those touting basslab....
last year at musikmesse frankfurt, i heard a black basslab soul IV being slapped. it was a very nice slap sound, punchy, with a nice high end. then i realized, it was fretless !
i couldn't believe it was a fretless i was listening to.