Pure Strength is closer to how you would lift weights in a gym. It does not utitlize the pyramid system (like PLB/PUB. You might have a first set as a 'warm up' with a lighter weight, then you switch to a heavier weight and do 2-3 more sets (each set has anywhere from 10-16 reps). You do several different exercises per body part before moving on to a new body part. Pure Strength is different than Slow and Heavy in that you lift everything with either a single or two/two count. No 6/2 counts in these workouts. Pure Strength legs has a floorwork section which is basically glute tucks using the high step, inner thigh lifts using a body bar, and outer thigh lifts using a body bar. Cathe uses a 15 lb. body bar! I use my 8 lb Firm Sculpting Stick and fry every time. How she does it with 15 is beyond me!
If I had to make a comparison, I think the Pure Strength Series is closest in style to the new Gym Styles, although PS is done strictly with barbell and dumbbells and no pulse counts to speak of.
HTH!
Sabine