im trying to make the same decision!
i did consider the denon dn mc 6000 but i have two mc 2000’s and i feel claustrophobic playing them and press the wrong buttons quite often, the deck switch funtion i find completely unusable as the effect knobs etc are all in the wrong place and it takes too much mental strain to switch to the right deck under pressure. i liked how the mc 6000 has every feature you could possibly need but its all too cramped. also the buttons like cue 1 felt like they would wear out so i was always conscious that i should try to tap it less which isnt fun. so i ruled that out, i did really like the jog wheels on the denons with the touch sensetive platter on the top (which could be switched off) and the CDj style pitch control from touching the sides of the platter, does the vci 400 have that? the kontrols wheels look pretty rubbish as far as i can see. Also another deal breaker for me is the inputs and analogue mixe capability, can you run CD’s into the vci400/s4 and straight out of the mixer? i think in this sites review they said you need to rout it through traktor on the vci400, does that mean a timecode setup? i want to expand later and get cdjs and use them as a bakup should my latptop go into meltdwn. also the lack of rca out is a minor inconvenience on the vci 400. but everything else on it looks perfect. is it a case of good jog wheels or no analoge mixer?