i've been running the 1267 & 1268 through my spectrum 3001 receiver & helios transmitter with spectrum pro module with LiFe 1450 rx batt for the last 3 month every 2nd day without any problems what so ever, & getting about 90 minutes runtime & recharging at about 6.2 v.
a lot of mates have the DX3S & are having lots of problems running digital servos, those that changed to the DX3R have no problems at all.
i'll change to my spectrum 3000 rx & see if there's any difference.