I tried sleeping on my side last night to get number of obstructions down, and I think it worked. I had the least number of obstructions so far now I have a data logging machine.
I suspect that I had a bad night is because my hips and shoulders are aching and that, to me, kept me awake for a lot of the night. Of course that is not really the case, I am sure I slept well, but boy, do I feel rough in the body this morning. The head is okay I am pleased to say.
This is a ying/yang thing. Back sleep well and endure a higher number of obstructions or side sleep and wake feeling sore but lower obstructions?
The difference in AHI is <3 V. <1.5 so roughly half. I think I will try back sleeping tonight - only 16 hours to wait!!