Federal Trademark Rights?

I have been using a product name for over 20 years and I never applied for a trademark. I now want to apply for a federal trademark. Does that application give me any additional rights -- like filing a federal lawsuit -- or do I have to wait for the actual trademark registration? I hear it can take a year to get the registration. I ask b/c recently my product name is being used by third parties and I've sent cease and desist letters so now I want to take action and am not sure if I have to wait until the federal trademark is actually registered before I can sue them in federal court. I know I can sue in state court based on my past use but I hear that the federal trademark protects me more.