I think 5X5 is good for beginners if your doing the main lifts and just getting a base level of strength and learning basic form. It will build a good foundation of strength which can carry onto learning how to program. It's not for isolation exercises.

I started off with Starting Strength which was 5X3 using only basic lifts such as SQ, Bench, DL, OHP, Power Cleans. Almost the same thing as 5X5.