When the W2 first came out it was said that it outflowed every factory head in production at the time. That's hot.
There have been many improvements over the years, combustion chamber being the best change IMHO.
Prices seem high until you start comparing bare for bare with aftermarket cast iron race heads for the smallblock chevy crowd, then they don't look so bad. Cast iron heads aren't so much cheaper any more.

R.