The NSA's utility overseas during combat in Iraq and Afghanistan with cell phone targeting <--> drone strikes was incredibly valuable IMO. They've put other countries signals agencies to shame by comparison, which is a very valuable national security advantage and provide an effective deterrence from superpower threats such as Russia/China, beyond simply nukes.

In war time I believe there is no doubt of their value.

But the lack of tangible tactical results in terms of data (in the broader fight against terrorism, domestic and otherwise) they have so far provided to the public is almost sad and embarrassing... considering the expenditure. So far they can only point to a small number of "real" terrorists or threats which they neutralized.

Results should be the only thing that matters.

Most of it would be in trade deals and other global political diplomacy that we'd never know about. Regardless of the technical capabilities that Snowden revealed.

The singular thing that scares me - that I can say with absolute certainty is immoral and dangerous - are secret rubber-stamp FISA courts.