The second-generation Sony D-100 was my second portable CD player. The first was a first-generation Sony D-7. Being an early adopter, I suffered through several problems with the D-7, but it was worth it to have "CD Quality" sound with me wherever I went.
The D-100, however, was much more reliable and was my constant companion for half a dozen years or so. The only problem it had was a dodgy headphone jack that kept coming unsoldered from the main circuit board, necessitating numerous self-repairs over the lifespan of the unit.
I don't remember what ultimately happened to either player, but my need for a portable CD player was eventually usurped when I got into Minidisc in the late 90s and the early 00s; a technology vastly superior for portable music, but ultimately made obsolete by the iPod.