>>
>>The other camp says that the PK should only be applied to non-deleted records. You can build a filtered index on the PK that ignores deleted records. Keep in mind that a filtered index will not be used by Rushmore.
>
>. . .but of course a second index on the same field but without the filter puts Rushmore into action again.

Yup. Just keep remember there is additional overhead to update a second, and IMO, unneeded index. Don't reuse keys and the problem won't exist.