Thoughts on second attempt: All of the gouge, study guides (especially atrickplay's), and practice tests on this forum are invaluable resources and knowing them inside and out will help you get a good score. Knowing that stuff will help you shoot by 70% of the questions in just a couple seconds each without any doubt in your mind that its correct or not. The other 30% of the test is stuff that needs to be acquired long term, through flight experience or just general passion and interest for aviation and science. Also helps a lot to have a technical major like science or engineering because it helps you solve some of those tougher problems that you might not have an answer for right away. Chipping away at the FAA handbook or a student pilot textbook over a period of 6 months can help out a ton as well.
I thought differences between form 3 and 5 were minimal. It was almost 2 years between my attempts and a lot of the questions looked familiar.