Fair enough, but their marketing stuff aside, the energy comparison would depend one what brenneke model, as some are equivalent. And non-expanding isn't necessarily a drawback for some applications, if the alternative is over-expansion. I wouldn't be as interested in alternatives if I could get my hands on some brennekes, but they don't seem to be available in Canada, or at best intermittently from very few suppliers.
At any rate, Italian can't get the ones the op was wondering about, nor the rws brenneke style slugs. None of their distributors are bringing them in. They weren't too sure why, possibly lack of demand or import restrictions.
I did some penetration tests on the weekend which are relevant to this topic with a range of products, if anyone's interested. I'll post that in the ammo section in my homemade slug thread later, need to clean and take pics of recovered ammo and organize pics.