Hi Dibz,
I agree with Zaki. Whether you want to call constant_load trochoidal milling or not, the fact is that the trochoidal milling that you see in Delcam will be in cut about 25% of the time (at best). While constant_load stays in cut 50%+ in the worst case.
Constant_load puts the tool in cutting at its maximum programmed load, and keeps it there as long as possible, before coming out of it. Trocoidal puts the toolin cutting at its maximum programmed load, and as soon as it reaches the programmed load, it starts to move the tool out. I do not see this could be more efficient.
Properly used, constant_load allows you to be a lot more aggressive in step_depth because you do not need to guard against load spikes.