Choices with a digital pen are limited right now. I haven't see the Fujitsu yet, so I can't comment on it. I don't find the lag to be a problem on my Vaio Duo 11, it seems to have picked up speed after a few Windows updates including a graphics driver update. I'd pick the Duo 11 if you'll need a keyboard frequently since it's just easier to carry. The Samsung is good if you primarily want a slate.
-------------------- Lisa Gade Editor in Chief, MobileTechReview