Each year I go to both, and I always have favored halloween horror nights. But, this year I think Howl-O-Scream is a bit better. The walkthroughs are just more intricate, and don't seem as packed. However, the Bill and Ted show blows everything else out of the water, and it's not like the houses are bad at Halloween Horror nights by any means, I just think they could be a bit better.I have only been to HHN, not HOS. So I can't judge. I heard the new house was really good and it was one of the best of the year.
Also, I wish they would have expanded the Scarezones for HHN since they have put it in Universal.