I purchased (4) 7 day unlimited passes for our Universal visit in May, I looked at the express past plus option but didn't notice you can scroll down the screen to get pick from different dates. First...is it worth getting the pass for a 2 day weekend? Also can I still purchase this option even I already have the park tickets purchased electronically? Also if I can buy them...which park would be better to get it for out of the 2? I am going to get just a 1 day express plus pass to one park.