One with the Shield is one of those 2.0 t9s. It's only a -60% end drain at the end, which most well built toons should be able to shrug off.
It's also an easy one slot pick if you need to mule some unique IO, which can even help a little if you find yourself in a spot where you actually need it.
edit: That said, you definitely do not *have* to take it if you don't feel like it would be something you'd need or use. Doesn't make or break shield/ at all.