I am pleased to report that after an 8 game winning streak my group finally had its first loss.
It was a 4 man with the dunwich, king in yellow, and lurker expansions (no lurker just the gates).
My group started off with no weapons, and 2 gate appears encounters that racked up the doom track in short order (one of the gate openings was also a doom gate, so we got 3 doom tokens during one encounter phase).
With monsters and terror track filling up, blight cards started hitting the deck, and soon the streets were filled with monsters.
We went to the AO barely able to get any footing, but even with all of that we were only 2 successes away from beating him.
My group was very pleased we finally found the difficulty we were looking for. We also would like to thank you all for some of the houserule ideas you've posted. We may go ahead and bump some of the AO's difficulty. After this fight (which again was barely a loss even with no items and one player getting devoured off the bat), we can see why a good team can just curb stomp many AO's.
