Alex,
Very interesting question. As a business owner that has had several SEO companies do our work( in my opinion) won't trust my keys to the kingdom. I have spent a tremendous about of money using services and outsourcing. I've learned that we do a better job ourselves and we understand our end user better as well as the product. I do still use 2 services( by the same company) I like how they operate, they are always straight forward and honest. One of the services is pure consulting- it's been invaluable. I have learned that I typically am dead on with my thinking, I just need to approach it from a computer mind a bit.
Good luck - might be easier to delegate some of your other responsibilities.
PS- if they start down the road of " Intellectual Property or I can show you a webinar" run....
Chad