As far as most players I've encountered in pugs, I'd say tank=heals>dps. This is mainly due to those who, while still putting out decent damage, pay no attention to what's going on and are really the dps'ers that piss off the tanks and heals. The GOOD dps'ers who actually pay attention, watch for stuff on the ground, keep an eye on their agro and such will actually feel more stress. And, imho, if your not getting some kind of stress and challenge, how can it really be that much fun? When I feel like playing lazy, I go fishing.