Dropping your guitar tuning to drop C is pretty much to get a lower end feel to what a 7 string guitar has. You can really get those low powerfull chugs. If you want a heavier sound, go with a drop C tuning. But dropping your tuning doesnt alwayse have to be because you want a heavier sound, you can also get a different feel of what your playing. It's fun to play around with different tuning and see what you like. I would try it out, play around with it.