the hybrids I've seen, and held, have been almost the same as a Commons.
Scapulars, head shape and "dot" are intermediate and "obvious" as soon as you see the bird in hand.
Head shape is also "intermediate" on those birds that I've seen.
Bills seem to be closer to Barrows than Commons and definately the location of the nostril, (nares), seems to be closer to a Barrows, (thats strictly "eyeball" as I've never measured the two and that cold be an illusion that doesn't prove out).
Paul's bird has more "green" in it than any of the others that I've seen.
Steve