Grant, that would appear to be it (network). 😀 When I move this test down to my local box I get identical results - makes sense because there is no...

Execution Plans attached:

EP_Nvarchar.sqlplan

select top 10000 PhraseDetailsId, Phrase from PMD-- results takes 14 seconds

EP_Cast.sqlplan

select top 10000 PhraseDetailsId, cast(Phrase as varchar(8000)) from PMD-- result takes 7 seconds

(needed to put 'top' in for...