The largest four cogs are made of titanium to reduce weight over the all-steel cassette. These Campagnolo sprockets use the Ultra-Drive system and are the fruit of continuous research and development to improve shifting. The Ultra-Drive system makes shifting more precise and fluid, especially thanks to the careful machining and treatments that the sprocket teeth have undergone. The special sprockets pattern interfaces perfectly with the rest of the drivetrain components, especially the chain and chainrings, thus bringing performance to levels of outstanding excellence.
Campy Record as expected provides an excellent component, reliable, very fast and accurate. I use one, it is the best. Reading your description I assure you that the four largest cogs are made out of titanimum not three as you desribe it.