What is "west coast sound"

Taking Kurt_tank's analogy a little further... maybe the "West Coast" sound is more finessed, quicker and leaner (brighter, detailed?). As opposed to heavier, powerful, etc. (warmer, laid back?)

Funny, it's also the first time I've heard of this term.

I've heard the expression with jazz, not with CD players.

I think it means that even though it is load of crap, the more liberal you are the better it will sound.

West coast sound has meant relatively bright with a midrange emphasis. It was coined back in the sixties. We had the West coast sound as in JBL Century 100's and Advents with the better bass but recessed highs and more bloom. The east coast sound (or New England)sound was usually meant for AR's, old KLH's, Advents, Boston Acoustics, etc.
Now Vandersteen's sound kind of like east coast and Joseph Audio and some of the like would be west coast.
I assume the reviewer thought the CD player was lively with some emphasis in the mids to upper frequencies vs something like an old Rega Planet.

Bigtee got it right. Jrd351, too. The market was dominated by JBL (made on the West Coast) and AR (made in New England). Regional stereotypes (sorry) were reinforced by the conservative (flat, but a little compressed) sound of AR versus the more colorful (with ear-pleasing emphasis of highs and lows, and more dynamic) sound of JBLs, a la the respective social styles and mores.

I believe, in Jazz, it was used to describe the performance style of artists like Dave Brubeck, Paul Desmond, Gerry Mulligan (early), and others, offering an “easier-feeling”, less-driven performance style. "Cool." (Not to be mistaken with the "Cool" of, let's say, Miles Davis.)