I had been flying my 550e with a 3G system for nearly three seasons using a CC ICE 100 ESC and its internal BEC. Late this past season the 3G began giving me random tail kicks.
At that point I replaced it with a 3GX system, V2.1, and continued to use it with the CC ICE 100 and its built-in BEC.
When V3.0 was rolled out, and I loaded it on my 550e, all hell broke loose. If I even so much as tapped the 3GX, the servos would go nuts and my AR7000/Satellite system would start flashing and blinking.
I reverted to V2.1, all was right with the world. Tried this experiment at least three more times, always with the same results.
I contacted the folk at Grand RC since they are an Align distributor, asking if there were any places where Align electronics could be repaired (I already think I knew the answer, but decided to press the question anyway). I never actually got THAT question answered, however the folks at Grand suggested I try an external BEC with more amp capacity.
I happened to have a new CC BEC Pro, so I hooked it up and gave it a shot. With V3.0 installed, and with the BEC Pro running things, the system once again is rock solid.
So yes, the answer is that when you convert from V2.1 to V3.0, you should make sure your power source is up to the task, otherwise you will have problems.
The CC ICE 100 is rated at 5 amps, but I suspect that's not a continuous rating. If I could manage to find some time, and didn't want to mess up a heli that I've upgraded and re-programmed, I'd go do some current measurements between a V2.1 system and a V3.0 system.
The 3GX works fine, by the way. No reason to dump it. It's really disconcerting to continually see "suggestions" to dump Brand X and buy Brand Z as the solution to all that ails. It's what makes an otherwise useful discussion turn into a "mine is better than yours" battle.
In this particular case, the suggestion to dump the 3GX and buy something else actually does NOTHING to fix the underlying problem - an inadequate power source. It actually tells you to put your money in the wrong place and solves nothing.
* Making the World Better -- One Helicopter at a time! *