I have used both products and I like SE creme much better. The Elasta Mango Butter just kinda sat on my hair, it didn't really moisturize for me although it did smell yummy. The SE is very rich and creamy, for comparison sake NTM Silk Touch is more watery in texture.
I've never used Silk Elements, but I have used the Elasta Mango Butter. The mango butter smells and looks good, but it didn't do much for my hair. It was very hard to rub between hands. I tried mixing it with coconut oil, but that didn't help either because it still just sat on my hair. And if you leave the lid off of it, it has the tendency to darken and become more plastic-y.