There is some controversy in our area that Leyland Cypress are very suseptible to some sort of fungus and that we should not plant them. Does anyone know about such a thing and is there anything to worry about?

Howard commented on the Leylands in an article:
He says he likes them, but
'Too much water and inadequate drainage will cause severe problems. Synthetic fertilizers and toxic pesticides make the situation worse. The solution is the Sick Tree Treatment followed by a total organic program, improved drainage and carefully managed irrigation.'

So If you are already on a good organic program and take extra care, you might be able to make them work. Making sure you get horticultural cornmeal out there one or twice a year will definitely help. Any serious fungus issues can be dealt with by using potassium bicarbonate on it. If that's not available, sodium bicarbonate (baking soda) will be fine.

_________________
Shepherd of the Trees
It is not our part to master all the tides of the world, but to do what is in us for the succor of those years wherein we are set, uprooting the evil in the fields we know so that those who live after may have clean earth to till.

Leyland are know for getting Scleridia canker which is pretty host-specific to leylands and kin.