The V-4 is a great video mixer with lots of FX - and its easy to use. You can even replace the fader bar with a DJ crossfader, a feature for the hardcore VJ. If you look around online there is also software available that allows you to do some pretty cool tricks with the V4 interfaced with your computer. Any VJ will tell you that the V-4 is like a tank out in the field. Once you buy one you will most definitely come back for another.
the Roland V4 for theatre
The V4. Is being used in Kalamazoo College's production of Stuff Happens to mix 3 live video cameras and a computer video feed, all run by students. It has made the video look seemles and professional and was a snap to install. I would highly recomend it!