Re: JB muddy?
I'm not sure I'd call it muddy, but I would definitely call it "dark"- and in a warm or tonally dead guitar then it gets too dark, or perhaps "muddy" is the better word then. This is why I really dislike the the JB in a short scale (real)mahogany gibbo style guitar which are generally very warm/full sounding instruments. It usually sounds decent in one of the faux mahogany MIK/MIC imports, as they are usually brighter & lack the low end and mids of real mahogany thanks to the wood, and pot metal bridges. JB helps to beef the amplified tone up.
IMO it's best in Alder and Ash bolt on neck fender scale guitars. I had an old strat with a full size JB I played exclusively for about 3 years that was excellent for anything from classic rock to late 80s shred metal ala Lynch- you just have to learn how to work the volume control on your guitar.
Jake's holdsworth died right before the 1st badlands album, so you can hear some good JB tones on Badlands and Voodoo Highway, though be careful as some of those tunes were done with a real deal late 50s black beauty & a Telecaster.
I'd also agree with the pick attack comment above- the JB is a "lazy" pup, and will "play itself" so to speak, and sound very lame doing so (for a good example see Jannick Gers)- but Jake is an outstanding example of what happens with a JB when you actually have a dynamic playing/picking style. And of course, Jeff Beck. You cannot pussy around with a JB and expect it to sound good.