> I am trying to decide if I should go with the complementary output instead of the single ended one. Most of the power seems to go to heating the room on the single ended output instead of driving the load.
> Well, of course that's the Way of class A....
Yes and no.
What we have here is one-sided class A. To get 70mA peak load current, we use a 70mA current source. That forces the active device to swing 0mA-140mA. This is hard work, and not necessarily low distortion.
Maximum efficiency of this plan is 25%.
Actually it looks like you are asking 30mA peak load current, using a 70mA current source so the active device only has to swing 40mA-100mA, not a great variation of Gm. But max eff is below 12%.
We don't have true current sources. We have current limiters that have to be fed excess voltage. You could cut power waste in half with a true current source. You can come pretty close, over the audio band, with a good coil (though that loses the convenient bias-setting). With a coil, max efficiency is 50%, though often more like 33% or 25% to reduce GM variation and THD.
Now if you can drive two devices in true push-pull, you can get back to 50% efficiency and also have a first-order cancellation of GM swing and THD. If you want 30mA peak load current, idle the devices at 15mA, swinging 0mA to 30mA to drive the load. Or maybe 20mA idle, swinging 5mA-35mA. Gm will vary from (expressed as dynamic emitter resistance) 1.5Ω idle, 6Ω to 0.8Ω swing. This is a total output resistance of 0.75Ω idle, 0.7Ω at peak swing, nice and constant. (Adding emitter resistors reduces the percent change, but not the absolute variation of output resistance.)
But if you have come this far, it is worth looking at class B. Or really: class A for low outputs or low load resistances, class B to carry big outputs in low loads. Most of your loads are really 2K or even 10K. And you rarely swing 15V peaks, and might rarely hear distortion if it only happens on peaks. 10V peak in 10K is 1mA peak, idle the pair at 0.5mA. This cuts power demand to 1% of your pull-only over-biased class A output. You may still demand 30mA peaks in 600Ω, which leads to a series of compromises with current swing, bias resistors, and thermal stability. But loudspeaker amplifiers are often worked 50mA idle 3A peaks, the same ratio, and they can sound good and be thermally stable when done right. Or for this small-scale low-compromise project, you might aim at 5mA-10mA idle, still a LOT less heat and power-supply than the 70mA pull-only output.