I know, I'm just a little gunshy of aluminum heads. In my limited experience with them, if you blow a radiator hose in traffic you're likely to overheat and crack a head by the time you can pull off the road.
Thankfully, I can look forward to several hundred thousand more miles on my Cummins 6B. But even Cummins, I hear, is going to aluminum cylinder heads on their new V6 and V8 engines.