Professional help is not a shortcut.
Do not expect your manuscript or screenplay to come back to you as a perfect specimen. Be prepared to work hard, probably for several months, integrating your consultant's comments and suggestions into your work.
Professional help is not praise.
Don't expect the editor to proclaim your work a pleasure to read and insist on refunding your money because your talent is clearly exceptional. If you want love and acceptance, get a dog. These services are for writers who sincerely desire an honest, professional opinion and can accept criticism and comments with an open mind.
Professional help is not access to an editor's Rolodex.
Although some editors will scout manuscripts for agents and producers, the odds of them passing your work to higher-ups are slim. It does happen. Sometimes. Just don't count on it. Paying a pro for a critique doesn't mean that they are obligated to stamp their personal "recommended" on your project.