I just did the premix w/ 3 sets of each exercise and my abs were the sorest part on me the next day (and the day after that!) But then I had been doing the GS series for a while so that may be why that particular premix did not make me very sore. do you have Pyramid Upper Body? I borrowed it from my SIL and the first time i did it my biceps hurt for at least 2 days after! it is an awesome workout!!!!
anyway, to answer your question, i find that doing only one set is not enough for me. i need way more than that to get a good workout.