mp3 can play from flash memory, which is solid state, no moving parts.
e.g.
http://www.d-mpro.com/users/folder.a...9&SubCatID=179 (I'm not saying i recommend this specific model for djs)
i agree, mp3s don't sound that great (though they are ok for most purposes at the higher bitrates). but i said the main advantage of the SL1200 is reliability and mp3s played from flash rom are more reliable.
and yes i prefer the sound of vinyl (esp for club music), the various imperfections do improve the sound - but all turntables play vinyl, not just SL1200s...
true enough you can be creative with the same old trues, i overstated that. but the fact is that new tools open up creative options, and the SL1200 isn't anywhere on that.