I haven't heard any boutique basses, however, the best sounding bass I've heard was a Music Man Stingray as played by Pat Seals of Flyleaf.
The sheer amount of bass in the mix at that concert blew me away, and the incredible sound of the Stingray made it that much better.
Is it just the Music Man that gives Pat Seals his sound? This is the sound I have been chasing. I need to figure out how I can get that tone and feel.
Thanks.