the g2 is very light and handy. you can load the .45-70 to trapdoor loads, as i understand it. besides, the rifle weighs 5 pounds. you definitely do not want to be shooting heavy loads in it or your shoulder will quit on you.
if i were buying, i would be looking at the encore. mostly because if you intend to use it for more than one thing, you run into too many problems with only being able to use certain cartridges with the g2, whereas the encore can handle them all.
-Matt