Since this keeps coming up, when nothing else will ....
I've seen that the side effects of each 6-month shot vary widely. I suppose it has to do with the timing, and what level my T was at the time. But yes, each period after a shot has been different.
As to the 6-month shot, it is all my insurance will pay for. They are trying to save a buck or two on cost and doctor's office fees. They even made me go through a review and appeal for the last one (Jan '16), so the gap was bigger, and the SEs have been much more pronounced these last few weeks.