Yaz or Yasmin?

Dear All, I am so confused about which pill I should take. I am on my 4th month of Yaz and so far no really serious negative side affects. I was hoping to clear some of my concerns out by reading other women's opinion but I got even more lost. I started taking Yaz primarily due to my acne problem. I am 37 and I am having the worst skin ever. Also, I have PCOS. But I was off the pill for two years anf finding no other way to control my acne problem (tried lots of OTC products without success), I decided to see my Doctor who prescribed me Yaz. I have not seeing any major improvement on my skin yet. Perhaps I should give to it a little more time... I have called my Doc's office to switch to Yasmin but I am not so certain I should do it. So far, Yaz has reduced my period days and made it a lot lighter. Very expensive though. Any suggestions?