I have no idea on battery life, but I can tell you that which one is better will boil down to preference and how your eyes physically work. Some people pick up green better than red. Others (like myself) find that they can pick up red better than green. Personally I would go with red as I find that I can pick that color up faster across a broader range of backgrounds and lighting conditions.
Also, keep in mind that an illuminated etched reticle will not stand out nearly as brightly as a red dot at equal power levels. The illumination of that reticle might wash out in brighter light, but you'll still have a very fine blacked out reticle to work with. Should you encounter something that is darker while out in brighter conditions, that illumination will take over and stand out for you.