The G2 being nitrolon, will probably withstand more in the sense of body damage. But since it is using a bulb, it can spoil with great impact and life of the bulb will definitely lose to an LED.
The Fenix is HAIII coated, but Fenix's HAIII isn't the most durable stuff. You might get scuffs and all that, but it does not affect operation of the light. The LED itself is 'shockproof' while inside the light. Great impacts might damage the converter/wires/electronics inside though.
So overall, do you want to protect the body or the bulb/LED? Fenix prob can suffice as a medium duty light and still work fine.
Anyway, if you are on budget, get a Jetbeam CL-E, Rexlight or wait for Jetbeam MkIIx. These lights cost around the same as G2 (MkIIx still unannounced), and have everything the Fenix P1D CE has. (except they are AA size, but if u don't mind even a G2, that's not an issue)
The Jetbeam's HAIII is pretty tough stuff too (at least based on the old models) and will hold up well against scratches. As to shock resistance, I guess minor drops and stuff will still be ok.