Put yourself to the test. You try to get into the copy. You really do. But every page you look at reads as if its writer were half asleep. If you can't scan the copy without nodding off, chances are your customers will be snoring along with you.
All professional writers can provide drafts.
This gives the client a chance to review tone and feel, make any necessary tweaks, and make sure the writing is proceeding as planned. However, drafts are not unprofessional scribbling. The copy you receive should be as professionally polished as your final product. Swear by deadlines. Your writer should consider deadlines to be an unbreakable bond.