The two products you've been using the SkinMedica TNS Recovery Complex and the Vitamin C&E Complex (antioxidants) are both excellent.  The TNS Essential Serum is their new "double pump" product and is more expensive.  It contains the TNS Recovery mixed with a different set of antioxidants, several peptides and more hydration.  It's a more complicated product.  Is it worth the extra money?  It's hard to know without good studies comparing the two regimens side to side.  In my opinion, if you are under 40 or have a limited budget, stick with what you have.  You might want to take on the extra expense if money isn't tight or you are older with significant sun damage.  Dr. I