Hello, I have been researching ICF's and found this article. http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html Written by the Oak Ridge National Labs that says that concrete walls with all the insulation on the exterior (none on the interior) utilize thermal mass much better. What are your thoughts?

You need to review a few things before following this practice. Its true in an oblique simplistic way that all the insulation on the exterior would perform better. It's also true that finishing the home entails more than just covering the insulation. That is why ICF blocks are used as a system, with the thermal mass protected on each side.
One example of potential problems with all on the exterior, is the interior thermal buffering is almost nil, because of the energy required to increase the surface temp is more than a covered mass. Therefore, you wouldn't want to use a setback stat in a heating locale because of the time it would take to increase the temp back to normal. Typically, the interior would stay stable in a two sided system; a one-sdied system works in a one-way transfer, so you need to keep the interior constant.

That's just a quick thought! I imagine though that one-sided systems have their use and place; probably in extreme heat or cold environments.