I started cheap with mine, but a good friend (top 10 IMAC competitor and local futaba rep) was using Futaba 3010's all the way around on his. He also intalled an O.S. .46 FX heli motor with a tower $15 muffler. I am using a Magnum .52 XLS, both engines hover between 3/4 and 7/8 throttle. No problems with any 3D moves with this "cheap" set up. We fly in San Antonio, Texas, where summer ambient exceeds 95 degrees and 880 ft. above seal level, which is wear and tear on engines and servos. The 3010's require NICD 6VDC battery only, most of us are using 1100's and Ace smart chargers. I think we are all exceeding over 300 flights on the .46 size, with only the normal tailwheel brake offs on hard harrier landings and the initial landing gear shear off on rough grass field landings.
We have a couple of "rich guys" running JR 8411's all the way around and use either the O.S. 50 SX with tower muffler or Saito .91. Most of us have the cg all the way back to the recommended rear limit. No one has had a nose heavy problem, with placing the batteries in the hollow space behind and under the throttle servo. The original cg range was ammended during later outputs of the kits, moving it way back. The airplane is still neutral and stable with the rear most cg, but tends to porpoise a little if trying to fly it in a straight slow line, but harriers and lands very slowly with this set up.
Hope this helps a little, if I crash mine, I will definitely go buy another, I would go into withdrawal without it.