Which one is tougher in actual use?
There is a ballistic gel penetration test on YouTube wherein the 140 BT does "better" than the 143 ELD-X, if penetrating straight and deep with a good mushroom is better, which many would say it is.
I tried to find the video but there are so many there I couldn't. Plenty to look at. I've not hunted with either of these, though I have a lot of them.
Rex