For 2008 Campagnolo has dispensed with the need to buy a front mech specific to the type of cranks and chainring set-up you are using. The new QS front mechs can have up to a 16 tooth difference between the inner and outer chainrings, and work with either standard or compact layout chainrings.
With Record featuring the carbon composite and alloy cage design, and Chorus featuring an alloy cage (weights are 72g and 76g respectively) it is no surprise that the Centaur front mech is a weighty beastie at over 90g.
The overall layout and shape is almost exactly the same as its two bigger and more expensive siblings, but the shifting seems tighter and more precise than the higher level mechs, and now works with the mech cage aligned straight, so no more having to angle it outwards slightly.
It just goes to show that steel could well be the best material for a front mech cage due to its stiffness and its wear resistance. Installation and set-up are simple and required a minimum amount of cable tweaking to shift perfectly.