RE: Jett .56LX vs West 52V1 for Magnum R
Hopefully 6-7 oz in the battery tray translates to a bit less in the tail. Although that area is pretty far back already.
The West engine is not overly bulky, and the Genesis pipe puts a fair amount of weight rearward compared to a tuned muffler.
At least with that honking prop on the front you can probably hand launch it vertically. Not so with clipped pylon props on the West, but once it hooked up.. ka-pwing!