Hi,
I love both series but find that the PS is easier to fit into my routine. It's older than S&H but it's really good. It doesn't require too much mental concentration and you work chest,shoulders and triceps at one time. Then you can give the back a more thorough workout along with biceps on another day. I like doing the PS Series on a swiss ball.
I prefer S&H Legs to PS SLA. Mostly because I like the way my lowerbody is right now and don't want too much legwork. Running pretty much keeps them tired. S&H, PLB ( 3 sets ) and PP seem to be just the right amount of strength training for my lowerbody without too much DOMS. Some people find S&H Legs easy because of the fewer reps. I love it.