It is important to understand that what makes the 5x5 work is not so much 5 sets by 5 reps, but the movements and frequency by which you are doing the movements combined with progression in load over time.
You can have a 5 day bodypart split that uses the 5 rep by 5 set scheme, but if you are only hitting those muscles 1 time per week the results will be far inferior to the 3 day full body 5x5.
This is a very difficult concept to accept. I personally would rather lift 7 days a week, however i've come to the conclusion that the optimal results for me as an intermediate lifter is the 3 day full body format.