Atrix has a larger 1930 Mah battery, though i haven't used an atrix, but bigger battery should mean long lasting battery....
I have used an arc, battery life is same as that on optimus rather wrse than 2x coz in that set the light sensor can't be turned off...
Sent from my Optimus 2X using XDA App
Dont Be SmaRt WeN Yo Are NOtt
Current Dvice~Samsung Galaxy S2 GT-I9100 with default ROM for the time bieng
Sony Ericsson Xperia Pro Mk16i- What a keyboard man !!
LG Optimus 2X with CM7-kangD by temasek << Second Fav fone
HTC sensation- Insertcoin 3.4.3-customized by self
SE xperiA NEΦ, 2.3.4 >> SE TWEAKED ROM
>>my fav yet
Nokia 5800>>loved the music quality