But for me, what really counts is the higher resolution.

"Customers -- particularly creative professionals -- wanted that and longer battery life," Nishimura said. "We looked long and hard at what is the optimal [viewing] experience. I think there's a point where you have to balance it with comfort so that people aren't squinting and people can find the icons. I really feel like we've hit it right."

Equally important, she said, is the added battery life.

"We've done that without making the battery larger or making the housing larger," Nishimura said. "We use a more energy efficient chip set, better power management with the AirPort [wireless hardware], and by using software to throttle back the [system] to an even slower speed. If you don't need the full processor, it will throttle back to 417 MHz."

She noted that the DDR2 RAM now used in the 15- and 17-in. models runs at a lower voltage, and the graphics processor also throttles back depending on what's happening on the screen. Those little changes combine to save juice.