Functional resumes are good when you have little to zero work experience (or new grads). This type of resume allows you to showcase skills that fit in with the job requirements. Fair warning: most recruiters and hiring managers dont like this format and feel as though you may be hiding something. If you have a chronological resume you do not want to have one part chronological and one part functional because it will throw off the entire formatting and may confuse the employer about your skill set.
No contact address is available. If the service does not have a physical location they may not be a suitable option for you. The chances are they are more into mass production of average documents. Numerous resume mills employ non-skilled individuals overseas to create these documents. They get hold of your current resume embellish it with the information available from the questionnaire and place it in a standard format.
The next thing you need to do to get a searchable job-winning resume is to incorporate keywords. Resume services can help you best weave keywords throughout your overall piece. Otherwise you can match up keywords from the job ad and integrate them into your resume. Using a core competencies section in your resume writing where you list out keyword phrases is also a good idea.