Well both have their advantages.
As far as features go, the VMS2 has some more features but they are accessed by the small buttons on the controller. Which is OK for me, but some people like bigger buttons. It has the great advantage that it is highly portable and the built quality on the VMS2 is very good. It also has a lot of cabling options. So overall very good unit.
The VCI-100 has a few less features, but has more space on the controller, so miss hitting something is not that critical. It also has the nicer jogwheels in terms of direct feel. It is also very nicely built and can get you a long way.
So basically both of them are not a huge miss for the budget they are in, depending on what you want to do and your DJing workflow one of the other will prolly suit your style better.
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