  Working at twist 2 accuracy and assuming the dominance of the Generalized
Parton Distribution H we study the helicity-dependent and independent cross
sections measured in Hall A, the beam spin asymmetries measured in Hall B at
Jefferson Laboratory and beam charge, beam spin and target spin asymmetries
measured by Hermes. We extract the real and imaginary parts of the Compton Form
Factor H, the latter being obtained with a 20--50% uncertainty. We pay extra
attention to the estimation of systematic errors on the extraction of H. We
discuss our results and compare to other extractions as well as to the popular
VGG model.
