I have a few tips for anyone in or trying to decide on ISP:
1. Get the Kaplan USMLE review books. They cover the high yield topics for each system, which if you know just what's in those books you can more than likely pass each module.
2. Get a copy of the USMLE DVDs, either bootlegged or they have a copy in the library. It's like having ur own professor telling you what are the pertinent points to know. I think it's just too hard sometimes to not be able to listen to certain subjects or have ur hand held a little bit.
3. This is very time consuming, but helps me greatly, especially for the clinical portions. Make flashcards.
4. Get the powerpoints, either by signing up for noteservice or downloading last years. This is especially helpful for micro.
5. There are a lot of completed modules floating around out there. They don't always 100% correlate with the current year objectives, but they are pretty close, which you can tweak. Get the module, print it out at Office Max with ur discount card and read through it 2-3 times.
ISP is not like I expected and I sometimes wondered what life would have been like had I stayed in lecture. Then I look at the LDP schedule and think there's no way I could have tolerated all that class. ISP gives you the core material you'll need to pass ur boards whereas LDP has a lot of extraneous fluff that the PhDs think you should know. ISP is also advantageous come board time, imo, because you can carve out more time to review during the semester. Looking back on the last two years, I wouldn't have chosen a different pathway.