COS is my adopted hometown. (Lived there for over 12 years) I'll be there this summer for a while. (I visit once or twice a year now. May move back there some time in the near future, still debating on that).
Avoid the south and east side of town, it's beginning to be called, Chicago Springs. Robberies, carjackings, shootings, etc. Avoid areas around East Fountain Blvd and Chelton Rd. Avoid Memorial Park and Dorchester Park. Downtown ok, many homeless. Marian House soup kitchen is on East Bijou St & Cascade Ave. I lived downtown and never had problems, just watch your surroundings.
Coywolf is right, I posted an article on this site that COS passed a law on RVs parking on the streets.
Good Luck!