There is a pretty big difference between 2012 & 2013. There are about twice as many 2013 videos as 2012, but the 2013 videos are about 20-25 minutes a piece, much shorter than most of 2012. That also means they worked in a lot more of their quiz questions, so that can be either a benefit or a hindrance, depending on how you study (I think it works better IMO). There are also a whole lot more of those really awkward to watch short clips at the end where they are trying to be be funny, but hey, sometime's it's the stupid stuff that sticks the best, whatever works!
I have been doing the 2013 version and have to say it has been well worth the money. I have had NBME questions that were based on factoids DIT gave me that weren't already in First Aid, plus the structure has been good. Do what you will, but just remember, after 6 figures of debt to pay for med school, I figure whatever extra costs I tack on to help me get good scores is worth it! 👍