Can we talk about the Deltas

I’m gonna state right away that I know next to nothing about the Delta Dagger and Delta Dart, but I know people keep on about them.
What was the difference between the Dagger and the Dart? They both look identical and it is very unusual for two versions of one US aircraft to be given different names.
Were they meant for different missions?
Was one of them an export model?
I know they saw action over Vietnam and Cyprus, how well did they perform?
Were they export success’s?
What did their pilots think of them?
Who was the last operator?

Any info,

Thanks in advance