The baffles that can be purchased are some sort of plastic or foam that is flexible and squeezes in between the rafters.
So, I can see division forming already here
-- I think I am going to have the poly foam guys in for an estimate and listen to what they have to say.
Right now, there are definitely no soffit vents. The loose fill is jammed all the way to the edges. Each corner of the attic is open to the air so presumably, air can get into the attic through those few spots and exit out the roof vents. Once it's finished, this won't be the case.
So if I install baffles, if I want true airflow, it's going to involve a bunch of soffit vent installation, plus baffles, plus extending the rafters in some way to bump up the R -- I am really starting to lean toward foam here!
Another thing regarding my roof.. it's asphalt now, probably 15 years old. Probably has 5 years of good life in it, and another 5 of deteriorating life. When roof replacement time comes along, I will probably install some sort of solar setup on the south slope (either water heat or cells) and the rest will be a metal roof. I will not be putting any more asphalt on this house, so if the longevity of roof argument only applies to asphalt, then I'm not going to put too much weight into that part of things.
I have some pictures in case anyone is interested. Sorry for the quality... crappy camera and bad lighting today http://photos.neenerneet.net/attic/