Pros
Williams has wonderful benefits, contributes to the betterment of the community, has many talented and intelligent people working for them. A permanent position with the company is definitely worthwhile, esp if you can get into a department with good management.
Kontras
Williams will lead contractors to believe a permanent job is on the horizon for them (one for certain was kept on a leash for 4 years), and then never deliver. I know of many who were treated as I was. They use the older contractors to train the younger college recruits, and then let the older contractors go, even ones who have been loyal contributors to Williams for over a year. Some of these "older" contractors were under 35! I was a contractor trying to get a permanent position with the company. A great deal of money was invested in training me which turned out to be a complete waste as a VP would not approve the position to be permanent. I noticed a great deal of resources spent in other areas as well that were seemingly wasted regularly due to politics and power struggles.