I've used a SCIO myself numerous times and I still don't know what to think. It doesn't need to be hooked up as the results are the same with or without the attachments. The concept behind it is that it uses a random generator and the things that essentially resonate more with a person will come up more. I used it somewhere around 40-50 times and even after all that I'm still not sure if it's simply coincidence or it really is picking up on something. There were times that the results were way off as well.
It seems to have been created in a way so that some negative results will always be given, as well a great deal of interpretation can be given to the results that come up. A great deal (if not all) of the results seem to coincide with the initial information a subject will fill in. So a person who checks off the smoking box in their personal info will have more issues arise than a person who doesn't (Not to say they shouldn't, but this is Always the case it seemed in my experience)
I can say that I still don't feel a whole lot better for having used it if at all and feel that there are better and cheaper ways to both test for things and heal the body.
As for testing I've always found EDS testing to be the most accurate and consistent in terms of sensitivities to environmental and food allergens. I've heard VERY good things about the Bi-Com but it's also very difficult to find a practitioner who uses one, I believe most are in Europe. You can read up on it here http://www.energetic-medicine.net/bicom.html