Personally, I don't like it. I would have preferred giving a coach a new opportunity instead of going with someone who has been through coaching a cycle a couple of times.
And as far as hiring him because of the 3-4 defense, the Cowboys were morphing more and more into a 4-3 late in the year. (And if the 3-4 is so grand, why were the two teams in the Super Bowl playing a 4-3).
We won't know for a couple of years if the Phillips hiring is a good one or not. Me, I'm betting on not.