This is all a matter of opinion. I am sure that you will have many different opinions. In addition, since the Bush plan did not get implemented, we will never know whether it would have worked. However, in my opinion, I believe that a smaller role of the government is always a good idea. There are three reasons for this.
First, generally speaking private company are much more effective than the government. This is partially due to a sense of ownership. When it is your money, then you tend to care more.
Second, if people are contributing to their future, then they will care more. To pay into a faceless system, which might not exist when you are older, does not really inspire people.
Finally, the government promises too much. I would hate to see what will happen if the government ever cannot deliver.