Ethanol blended gas (good or bad?)

My freind runs strait ethanol in his 69 road runner and was having a problem with his fuel pumps going south.
He had marvil mystery oil checked-- by testing--at some company for the specific gravity of the product.
It turns out that it has everything in it to help with lubing the pump and also to help with detonation problems because of low octane.
Plus it helps with ring wear with ethanol.
I thought this was funny because i have been using this stuff since the stone age and have always liked it.
I took my 360 apart after 10,000 miles and it had no ring wear at all.
This is 10,000 hard miles.
My engine's bottom end has a little over 20,000 on it now and was built in 1994.
I always run it in all my cars and this looks like a new reason to use it.