Maybe this will give you some insight into the detail of the books.
I took Cell Bio at my undergrad institution (Hopkins) and we used the gigantic (mol bio of the cell) Alberts book. It was a fantastic book, very informative and in-depth, and I would definitely recommend it to anybody who wants to gain a very specific understanding of molecules, interactions, and pathways in cells.
My roommate, who's Biomedical Engineering, used the smaller Alberts book in his "Molecules and Cells" class. He said they used it only so they could gain enough knowledge of the cell to begin applying mathematical formulae to them.
So in a sense, it's really up to you with how specific you want to go. As a Bio major, I just happened to love the gigantic Alberts book for its specificity.