Personally, if I had to choose between hamstring curls and the exercise depicted by highjumper10- I would go with the exercise depicted.
We use the exercise depicted as well as sub-max yielding hamstring curls for certain rehabilitative measures as well as very sub-max loads as part of active recovery (get blood flow going through the pumping action then move on to various forms of stretching); however, as a developmental or auxiliary element during day to day training I use hip extension moves exclusively for my skill players for reasons already discussed.
I answered a question the other day on EFS that partly addresses this issue as well:
Hamstring Question