But again, what you're saying here is purely anecdotal. Actually, it may not be, but I have absolutely no idea because the way you are presenting it is in a purely anecdotal way.
Is this not basic physics looking at pivot points? If 160+ pounds is landing on your heels, the shock of that must be absorbed entirely by your knees and hips. If the same weight lands on the the front of your feet, you have the added absorption offered by your toes, ankles, and achilles tendon. That's not exactly anecdotal.
As for the long-term health effects of one or the other, that's still being debated and might be dependent on the joint health of the individual runner. See [1].
I don't know if your heel touching the ground first is the same thing as what you're describing. I usually run as a 'midfoot' but I sometimes let my heel touch the ground first. I don't drop my weight onto it, though. I just roll the foot forwards. 'Heel striking' doesn't mean running on your heels.
As for the long-term health effects of one or the other, that's still being debated and might be dependent on the joint health of the individual runner. See [1].
[1] http://journals.lww.com/acsm-msse/Citation/2013/12000/Forefo...