I would prefer to have an employee who is a Y personality simply because motivation is more important than prior knowledge most of the time. If I want an employee who only does the bare minimum, I might take far longer to complete any sort of work or make any progress. Innovation comes from doing the maximum, not the minimum.

However, someone with a Y personality would be far more likely to do the work well. Knowledge can be taught but motivation, as previously stated, is much tougher to imbue.