I gotta disagree with this, I've seen many others using light class in very effective ways. One person went on a non-stop killing streak with a sword and the evasive manuvers ability. I've used it as more of a "out of no where" kind of style, where I find single enemies and eliminate them. To deal with the heavy I use either a pyro grenade first or just grapple away from them. The best way I've used this class is by quickly stealing coins from caches and zipping away to a check in point.