I just made 4" loop with about a 6" bury in the neck according Gqgeek's specs and it looks to be incredibly strong due to the fact that the amsteel is doubled all the way through the loop and back into the neck. Based on a superficial inspection, I would expect it to be stronger than than a regular hollow strand of amsteel and any failures would be in the standing line below the bury in the neck.

That said, the only real benefit I can see of using this method is that the loop is stiff enough that it will stay open, allowing you to clip into a biner with one hand. Whether that convenience is worth the time required to make the loop is your call.