I used Becker for all four parts (I don't actually take FAR until tomorrow), but I have passed the other 3 on the first try using it. Becker's material is fantastic, but you have to committ to doing all of the material. That means, lectures, MCQ, Sims, Practice Finals, etc. If you skip over things, you're only cheating yourself.
Becker is definitely my recommendation, but just make sure you are learning the underlying concepts behind the question and not just memorizing situations and answers. Especially with REG, since there are so many exceptions and exceptions to exceptions. It's difficult to memorize a situation and be able to apply it to a question on the exam.
Good luck on your test!
Becker Review Course - Done!!
BEC - 77, REG - 88, AUD - 90, FAR - 83