"Current" loyalty? More like a decade of loyalty.
It all comes down to whether or not you think President Bush is a good judge of character. How have his other judicial picks turned out? How have his executive picks been? Given his track history, I will trust his judgement in this case.
I don't trust men as much as track records - in this case hers (or lack thereof), not his.
I'd say that character is a necessary, but not a sufficient, virtue in SC justices. It takes far more than character to write and persuasively defend lasting opinions.
But your point does remind me of Leonard Leo's remark that Ms. Miers would likely move the court to the right but have no desireable impact on the national legal culture.