I have the 5th edition books and if you're worried about them being of inferior quality, don't. However, don't take my word for it since for all I know, EK's version 7 books may have been proven to make everyone who looks at them get automatic 40's!
The only gripes about the 5th ed books are some errors here and there, but nothing too bad. I did miss a question on a practice question somewhere because EK's organic book told me that a nitro group was NO3 - with a lone pair on the nitrogen.