You wanted to hear from one of the locals, well that it me. I live in Aurora and have my business in Aurora. When the park became SFO from GL and they expected a 40% increase in attendence we were concerned, mostly with traffic issues. Living in a community with two major seasonal parks, you get used to the traffic at certain times of the day, week, season. When planning your route in or out of the area you learn to look at your watch and plan accordingly. Based on the fact the amusement park had a 42% increase in visitation I would have to say they had did an excellent job with traffic management. I have clients with business on route 43 directly across from the park and they had no real complains as to how the traffic was handled. Of course the park had some issues with parking during a few of their busiest days but I attribute that to growing pains.
Like Jeff, I did not visit SWO last year. It was a park that I would only visit one every 5 years or so. Now that our season pass to SF include the use of the resources at the other end of the lake it becomes more of a "no-brainer" for most Aurora families to have season passes to the park.
I have a wife and two small kids and we are looking forward to doing some of the family things at the marine park. My retired parents purchased passes and it becomes a greater value to them since they don't ride the rides but will enjoy the marine park's shows and attractions. There will be more them to do when they take my kids over there on their own.
Down the street from the park a new retail center is going in with stores like Walmart, Home Depot, Kohls, and a Bob Evans. This will not help the traffic situation at all. Living in this area you take the good with the bad, there are ways of avoiding the traffic. It is exciting that so much is being invested in this park in our backyard and for a modestly priced season pass we can use the park all season.