I was gonna stick a bunch of info in here as to the differences between the two versions, but there's no point as most sites I just looked at refer to the workprint as the Directors Cut.
The following piece of text was taken from a review of the DC, suggesting that the follwing scene was included in the DC but not in the official R rated version
Surprisingly, the action scenes weren't the only bits cut. Also missing is a "love" scene between Van Damme and Butler.
The love scene wasn't in any version except for the workprint. The DC & the workprint are two different entities. Jesus, people are so retarded.
Note: the previous moan I just had wasn't directed at anyone here, just in general at fools on the internet.
By the way... cover & disc art for the workprint would be ace if you could create some, I'd try but my creative skills are fucking dreadful.