Open enrollment for health ins! Should I change to Aetna?

Hi all! Thanks so much for your help with my previous question!! It seems as if my Premera plan will not cover any sort of WLS surgery even though I have 52 BMI and am well above 100 pounds overweight. I will make a call to Premera tomorrow to make sure, but I have a week left in my open insurance enrollment and I have a chance to change to Aetna. Should I change to Aetna? Does it matter if it's an HMO, as opposed to a PPO program (what I have with Premera)? Have people had a particularly bad experience with Aetna? If I have to self pay I'll do it. After having had a small surgery scare which the doctors told me was probably caused, or at the very least worsened because of my weight, I don't see how I can afford not to.

Hi deffinatly look at the insures option in the small blue letter by top of page this will give you alot of info