With Traktor more so than Serato, effects can be used but they can also be altered and customized to fit whatever need you may encounter.  Regardless of how you map your effects, either through a physical mixer or through a software solution, you are bound to run into a few issues.  One of them is performance.  Anytime effects are used on a computer, it steals processing power from your computer.  Beside video effects, audio effects take a decent amount of resources to create and can put a strain on your CPU if you’re trying to use too many functions within one computer program. The other problem has to do with pre-fader and post-fader effects.  Since you’re not routing music through an external device it’s difficult to run your effects independently from you other software; but there are some clever ways to get around it. One way of using an effect bank like an external unit is by routing effects through a separate channel, maybe Deck “C” in Traktor Scratch Pro.  This gives you a semi-independent control over the effects using a channel on your mixer.  It’s not the same as having an external unit, but if will get your close to the look and touch of a hardware unit. http://www.djtechtools.com/2013/01/07/isolator-effect-mapping-in-traktor/