Might sound lame and vague but I'm primarily focused on having fun. When I read a check I look to see if the information is presented cleanly (aka is it a chore to read through?), if the setting grabs me, if the GM seems nice and if a potential character immediately comes to mind. A setting that's easy to create a character for is usually more fun for me, so I jump in. That's pretty much it, just whether I think it will be "fun" or not. Any genre, time period, theme, or feel is fine!