I havn't used one but for what I hear you should avoid using gemini due to their gerneraly poor build and product quality. when it comes to CD players in the DJ market I would really say that Pioneer are the top of the game, failing that Vestax or Denon but I don't think Vestax does a dual CD player. It might be worth while checking out the denon DND range? They will be a little more expensive that the gemini but well worth the difference because of the quality change. if the DND series are to much than Stanton dual players? their higher end turntables are reasonable so I think their CD players should pass the cut but then again I havn't used any, just trying to offer you some alternatives.

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Pioneer CDJ-200s, Sony MDR-V700DJ,ASUS M51Sn Ableton Live 8, Behringer BCF-2000, Behringer BCR-2000, Vestax VMC-004FX

I'm liking the Vestax VCi-300. It would be better for me if I just went straight off my computer. My main goal for DJing is to get songs (mostly hardstyle and/or trance) to just flow into each other smoothly and if I can do that with the Vestax then awesome.