Should I switch from Wix to Wordpress Shopping cart?

So 3 days ago a purchased an ecommerce package at Wix, it's a flash based website platform. But what concerns me is SEO. I still have the option for a refund, so I'm thinking of switching to Wordpress. But the thing id I want to hurry with setting up the website. What do you think? Is wix good or really bad at SEO and should I switch to Wordpress?