Crist,
I just like living on the edge!
Seriously, I am not sure. I originally chose the Nobler because it has a relatively thin airfoil so I was thinking it might be less draggy than the modern Fat airfoil stunter. I think to some extent, the fat airfoil is a development of having mucho power in the modern CL engine, and actually it helps hold back the engine in level flight. When the plane goes vertical, the airspeed drops a bit but the drag drops faster so it is a way to get some self regulation with the modern glow engine. With electric, I'm flying with a governor, so I don't really need the fatter airfoil. Of course I may be giving something up in square turns (more chance of stalling), but that depends on wing loading (low wing loadings need a lower angle of attack, so stalling is less probable). So my battery pack weighs in at 6.7 oz, not a lot more than stunt tank and 4 oz of fuel. Considering my motor only weighs 5.4 oz, and my speed control another 0.9oz, you can see my power package is pretty competitive (weight wise anyway) with a modern 35 sized engine and fuel setup. The entire ENobler weighs in a little less than 44 oz (and that is with the battery charged!).
Anyway in the end we will see if my batteries die a faster death than others, but I try to keep them at the 20% reserve level at the end of the pattern. Another reason are my batteries are a lot cheaper than most others ($62.25 a pack and now 10% off that), and probably that is the main reason!