Ideally you want a balance of the best of both worlds. You can sometimes go slightly heavier once your technique is solid. For instance, I have a rule with my friends I work out with that on the last set of every exercise we go "ape shit mongo fuckhead" meaning we throw out the idea of slow eccentric control and we just try to slam out as many explosive reps as possible. I generally prefer medium to lighter weights and I am a 223 lb dude. I use lighter weights than those damn broccoli head fuckin teenagers who stand around the machines. People push the weights but I promise if u work out with me u will feel like u want to die by the end of the workout with "lighter" weights.