I doubt that vibration kills many Airstream batteries.
In MY experience AGMs are just not worth the extra expense. When I pay a premium price for a product there is a sting when it does not meet expectation as it becomes totally worthless as fast or faster than a different product that costs half as much.
I can respect others who have had better experience with these things, but as for me, at this point and time I am done with these things.
From a financial point of view my experience does not support my purchase of AGM batteries.
On a different level, I see them as a "gadgetry thing" but their "gadget coolness is not a real or practical justification for their additional cost.
Gradiens super tenui glacie.