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.
I used to volunteer as a cuffing dummy for the Customs Department while I was in Guam. Sankyo is indeed a police favorite as far as aikido locks. Teaching them to do it properly is hillarious...reversals and such. The variation that they are taught at the academy is brutal (but a bit sloppy). I also learned a sankyo technique for moving a prone person who is on their back onto the belly to facilitate cuffing. No openings for the suspect to reach out and touch you no risk to the elbow either, though that doesn't mean it didn't hurt. Where aikido really shines is in prisoner transport. almost every lock can be used as a come-a-long and the general tactics of aikido arevery suitable to the job.