Fan or no Fan, that is the question.

Hi There
I am quite new to the incubation of chicken eggs (I just set my first batch today at noon!), but I am happy to share what little I know so far.

When I finally decided to purchase an incubator I settled on a model that circulates the air with a fan, my thought being that circulated air would allow the heat to be more evenly distributed through the incubator. This would likely avoid the top of the incubator being say 100 degrees and the bottom of the eggs maybe being a degree or so cooler, say 98-99 degrees.
If you think of it like a convection oven (sorry chickies!) versus a conventional oven, the convection oven has fans that circulate the hot air leading to more evenly and quickly cooking food. Now while the goal is definitely not to cook the little eggs, I think the more even heat could only help ensure proper incubation conditions.
Also, chickens need fresh air for proper health, so I would think that well circulated and ventilated air would be more appropriate than air that may just sit stagnant in the incubator. The developing chicks are not breathing the air, but the porous egg shell certainly breathes in its own way.
I would be interested to hear more info and especially the other side of the story from someone with more experience on the matter.
Hope this helps a bit. I was perusing the threads waiting for someone to respond to my post.... no one has yet, so maybe it is just a slow night on the BYC forums?