Harrison is probably a bit better. But it's tough to tell since Harrison has Eugene Wilson covering massive amounts of the field while Roy has had Keith Davis, Willie Pile, and Lynn Scott.
One thing about Harrison, he gets away with more blatant holds....like him grabbing ahold of a receiver's jersey where you can see a good foot of jersey in his hands. Refs rarely call it.
I'd probably take Roy in defending the run, give the slight edge to Harrison in blitzing, Roy the edge in deep coverage, and Harrison the edge in short coverage.
Rich.........