pulsing 'next gen' leds doesn't yield any more brightness, perceived or average. the best way to get more light from most power leds is to lower the junction temperature. if you can keep the junction at 25C or less, you can keep upping the current until the internal bond structure can't take it anymore.
on the other hand, some new leds produce more light at higher temperatures, but you sacrifice longevity for brightness. The luxeon rebel works like this. you can run them at 350ma for years and years, or run them at 700+ma for months, at nearly double the brightness. The luxeon PWT is an even more extreme example of this. The pwt is rated to last a mere 2000 hrs, but cranks out 26 lumens from roughly a 0805 package