Personally I kinda like both. Some days I will start out doing sets of 25-35 at a moderate weight, and maybe do two sets of each exercise for the part I'm exercising that day. Then I'll switch to the heavy stuff and do a few sets of 8-10 to finish my lifting. I think the key is this-when you're done, do you feel it? How about the next day? Are you still feeling like you worked your ass off?If the answer is "Yes" then your exercise routine is probably effective.