Hey UTMonkey. One thing you may run into (I did when trying something with it) with that interrupt code of mine is that if you want to blink the LEDs very fast you'll get odd results as the speed of blinking starts to get too close to the interrupt display updates. Odd harmonics happen and LEDs blink for too short a period or don't light at all because they were on and off before their update came.
At that point you either have to crank up the interrupt rate (I would think it should be possible at 8MHz) or find another way to do it. At low blink rates or LEDs on all the time it works just fine.
I was trying to do my VR1/VR2 blinky program with the interrupt code above. Wouldn't work at all except at the lower speeds.