a two step usually takes about 5-6 hours for me...a three step about 9 hours...4 hours compounding, 1.5 hours polishing, 1 hour final polishing, then all the little things like vacuuming, tires, wheels, dressing, windows, trim, wells, etc...this is for a small car by the way, a full size truck three step takes in the 12 hour range...
oh and if you are using optimum, that is your problem right there. On one hand its a good product to be used in the sun and via rotary, on the other hand, it royally sucks viz PC and in a garage as it takes WAY too long to break down via PC