Reply to Help please, vci-400 or s4

So have been using the S2 for 4 months now, and i want to upgrade to a 4 channel controller.

so naturally i want to move to the S4, because 5 of my friends have them and they love it. and i am looking
around for the price on this. cheapest probably on ebay for around 650$.

HOWEVER, yesterday i stumbled on the VCI-400 about it can be a standalone mixer. (awesome feature)

i can buy the VCI new for 650$ also. i love that it has more buttons. (to me more button means LESS of SHIFT function to get to a secondary mapping).

so my question is the stability of the the VCI while playing at clubs??

thanks