Of course you can complete business school applications without a consultant. However, using a consultant might make the process easier for you and it would likely improve the overall application package. Consultants will be able to give you honest feedback on your essays and your resume and help you objectively understand how to position yourself. They will help you understand your strengths (and how to convey them) as well as give you strategies for mitigating your weaknesses.

A consultant will not write your essays for you so it doesn't really lighten your workload, but you may find that the process is more efficient when you have someone else as a sounding board.

If you are confident in your writing abilities and if you feel you have a strong understanding of your strengths/weaknesses and of the process as a whole, you probably don't NEED to hire anyone. But, if the expense isn't an issue and if it would make you more confident in the final product then a consultant can't hurt.

As a consultant, I see a huge improvement in my clients' applications after we work together (or after they work with other consultants!). But, I didn't use a consultant when I applied to schools!

If you choose not to use a consultant, just make sure you have a friend or family member read your essays and make sure there aren't grammatical errors or typos (and to make sure that your application puts you in the best light possible!)

One more thing....you said that the consultants you spoke with had different opinions about your chances. There is no consultant out there who can guarantee that you will be admitted to a specific school. It is difficult for consultants to give clients an accurate idea of the schools to target (mainly because applicants usually have an idea of where they want to go and aren't always open to suggestions!).

As you know, business school is competitive. The admissions process is an art, not a science. Every year, very talented applicants are rejected from schools. A consultant can help suggest schools that might be a good fit for you but, after that, all a consultant can do is help you put yourself in the best light possible so that you have the best application that YOU can have.