S.T., I can't agree. There is a lot more to a Justice than how he/she votes. As one who has been through the law school process, I can tell you that what a judge writes matters greatly. We carefully examine the opinions, all of them (majority, concurring, dissenting), in order to get the full picture on religious liberty, free speech, interstate commerce, etc.
The great Princeton philosopher Robert George always urges his students to engage in the strongest possible lines of argument. In order to do that, you need the strongest possible arguers. We should pick our best and brightest, not our most comfortable, on the conservative side.
There is also the little matter that she is 60 years old and we give up a good decade of influence on the court, unnecessarily.