And I believe that your can get even better runtime from G3L with a malkoff dropin: P60LL 80 lumen for 8 hour in G2
Your will get about 50% extra runtime with a G3 compared to a G2.
+1 on the M60LL drop-in, with better modularity/upgradeability compared to the 'sealed' SureFires. You can drop it into better hosts or add a rechargeable battery system later, options you don't really have (for the most part) with the E1x.
And that's ~12 hours of
regulated output (compared to the
total usable output that SF states) from the 3-cell SureFires. You should expect another 3+ hours of
very usable light from a G3 (or better yet, a 9P) after the M60LL drops out of regulation. So really you are talking about 15+ hours of great light from a 3-cell body.
Unless you also want the additional low output option of the E1x, L1, etc...
Just buy both. I guarantee that both of them will end up being very useful, a small EDC and a larger utility 3-cell flashlight.
edit: oops, you already have an E1B. So try out a 3-cell w/ the M60LL, you won't be disappointed.