I imagine that the tests that you are referring to are practice in-service exams. They are meant as prepartory tests for the boards (board of internal medicine, not usmle), and are used by PD's to gauge what subjects their housestaff require more lectures in and to help their housestaff identify any weaknesses.
Are you talking about the MKSAP-13? (question book/cd for the boards?) If so, my school used the MKSAP-12, and I liked it a lot. It's similar to q-bank, except it's written for the IM boards plus it has a lot of practical clinical management info in it. I think that RWJ's IM program actually does questions from it every morning at 6AM (not a selling point for the program IMO ). Anyways, if my program doesn't provide it for us, I may purchase the CD within the next couple of years for the practice questions.