Basic Pathology, despite its name, is a fully fledged textbook which contains more detail than any med students will need. It has great coverage of any condition you will study as a student (provided it has pathologic basis: look elsewhere for theories behind psychiatric disorders).
Many say these two titles are like the baby Moore vs big Moore, but I say that they're more like big Moore vs Gray's Anatomy.
Basic Pathology will suit the vast majority of med students. Only buy the big Robbins if you're the obsessive type and want all the fineprint.
Regards
(edit): Forgot to add: A big advantage of the Basic Pathology is that it's light enough to carry to and from class, without having to resort to a huge rolling backpack and thus revealing the true identity behind the cool med student facade. 🙂