As nearly everyone seriously involved with the Winamp2.xx series can attest to, the vast majority of the 3rd party plug-ins were a disaster !!!
LOL
And, many plug-ins would work, but only ALONE ! Most did not deal too well with other plug-ins competing for resources... Ha Ha Ha !

Many of the plug-ins in the FS series of 'compilations are actually not so easy to find... All of them take hours and hours and hours to find, download, install and configure !
That does not include the even greater numbers of hours needed to test to see what actually works with what !

The Full Suite versions took out nearly all of the work for most users... Winamp was always a 'bit fiddly' (as the English say) to get it to work reliably and be able to use all of the great features it has...
I know many many people who just gave up and went back to Musicmatch Jukebox or whatever... And, that was back when the sound quality with MMJ was really bad !

Pity about the Winamp 5 series, but it was obvious what was coming by the rubbish of the 3 series and the crazy business games going on in the 'background' !