I have both. The G2 is my EDC. It's been dropped several times at distances from 6 to 10ft off the ground. Still has the original lamp in it and it's about 3 years old now. The 6P I don't use as much, I keep it on the nightstand for bumps in the night.
I think the Nitrolon has a little more flex to it so that may help when dropped. the G2 also has a lexan lens, so you won't break that either. The 6P has pyrex and it is possible to crack that if you drop the light hard enough and at the right angle. But at the same time, if you leave a G2 on long enough it will start to melt the lexan. I left mine on for an hour once while I was working on an A/C unit and it warped the lens. You won't do that with Pyrex.
Either way, they are both excellent lights. I highly recommend both of them.