I've been singing the PM SS praises since it first came out. I wouldn't say it provides slip but it makes your hair sooooo manageable, you'll never look at "slip" the same way. I have over 2 years worth of new growth (4a/b new growth at that) and I am able to comb through both textures just after using the shampoo! The trick for me is to towel dry (just wrap the towel around the hair for about 3-5 minutes to soak up the water) and then comb. Then I put the conditioner on it for like 15-20 minutes (10 minutes when I do it in the morning), rinse and then comb again since I put my hair in a ponytail.
Also, the hair separates very easily when it dries which is great when you flat iron with a fine-toothed comb.
The more you use it the better your hair gets (well at least for me it does). The ingredients are wonderful. I use the PM Hair Repair Treatment about once/month for extra strength but, other than that, I don't use anything else but the PM SS system (well I use the CHI silk infusion drops before I flat iron but the SS drops work just as well).