I have a design that I print up quite often for the special needs community (http://www.thingiverse.com/thing:148045) that has tons of overhangs on all sides. On my previous printer I had to wire up a good deal of additional cooling for the PLA to not curl. On the TAZ 5 the prints came out great on one side, but curled on the other. I tried to retrofit some of the TAZ fan ducts I found out in the forums, but they were all designed for the older hotend, not the hexagon, so they did not fit. I drew up a quick duct that tried to match the look and feel of the factory duct and put it up on thingiverse (http://www.thingiverse.com/thing:716002). It is thin enough that it does not not reduce the travel at all and requires no modification to the TAZ to mount.
It has fixed my overhang issues perfectly. Hope it helps anyone else who was having the curling issues.