Let's be honest. Jonathan Harker is a pretty thankless role. You're doomed to be cuckolded by Dracula and upstaged by Van Helsing. Quick, without consulting IMDB, who played Jonathan in the Bela Lugosi movie? In the Hammer Films version? In the Frank Langella version? In the Louis Jourdan version? In the Jack Palance version?
Nobody remembers Jonathan . . . .
And I confess I didn't recognize Katie McGrath at all, until Allyn pointed it out on-line.