I've heard from people who heard from cops that train in aikido that the suspects, when restrained with aikido locks and techniques are actually more cooperative and some say, "thanks for not hurting me!"
umm I've never taken judo but I've felt some judo throws... and they're not the most comfortable things in the world to expeirience sometimes, just my experience... I've heard the technique Sankyo (third teaching) is among a favorite of cops, I guess because it's a great restraining move in the sense that after they're in the lock they can't walk around or toward you.