Ideal, I think, would be the third way: partial but not stemming.
I'd much rather have partial matches without needing a "syntax" element like an asterisk to mark it. That is, I'd like to have a search for "driver" match "drivers", which would be a match on part of the word, but not "driving", which would be a match based on word stems.
Partial matching would solve Nancy's case of Holbrook versus Holbrooks, and it would allow one to do "psuedo-stemming". For example, searching for "driv" if one wanted to match both "drivers" and "driving". Note the "psuedo", as that would also match "drivel", which a true stemming search would not.