They both are based off the Same Core principles. If you go from Krav Studio to Krav Studio you will see small differences but the core of each move will be the same.
Haganah from what I have done and seen uses alot more of the higher level Krav Material at an earlier time. But at the end of the day they are pretty much the exact same thing.
The guy I train under is both a Krav and Haganah Sr. Instructor.
Krav Maga Instructor - Austin, Texas
"Do what it takes to go home safely"