If you'd like to view some of their work, 1-on-1-Resumes.com has a small library of Sample Resumes for your review.
Also, one thing that I learned in this process is that in order to have a Federal resume done, you have to have the exact job listing in hand in order for them to proceed.
4) Price. As discussed above, I feel as though their pricing is suspiciously low and to pay a professional writer I would expect to pay more. Also, their guarantee policy is pretty agressive - 1-on-1-Resumes.com claims that you will have an interview within 30 days or they'll re-write your resume for free.
5) Industry Affiliations. 1-on-1-Resumes.com is affiliated with the National Resume Writers Association.