I'm the complete opposite. I had so much trouble getting Great Works in a trade that I assumed the AI couldn't part with it under any circumstances.
I haven't tried post-patch, but pre patch, it seemed to significantly vary depending on if they were going for a cultural victory or if it was themed or not themed.
In addition, areas with more lakes seem to have fewer rivers.
, but the Settler increase has really messed up my build orders. I've always had 3-4 Settlers one turn from finishing pre-patch, then I allow the lowest production city to pop the first one (same with Builders). Usually you can get the entire pile to finish in maybe 5-7 turns. Now, even my best production city loses at least 3 turns, forget about other cities. So to play a peaceful building game, you have to run the card a crazy amount of time. So you might as well keep building Settlers in every city, even if those won't finish until the next round 30 turns later... Meanwhile the warmonger is running much better cards and not using hammers on Settlers to min/max. 
.