Not many people know about them and are highly skeptical. I ended up buying the full package for 100 dollars and I love them. They're a great way to spend my last month since ive exhausted every other resource. They have a very very good series for molecular bio, which was one of my weaker points. The visualizations really help you put things into perspective. Theres no crappy 1 min videos like some of the sample ones on youtube. The average is like 6-7 mins long. Most of the videos are excellent, although a few could require a bt more information. My only complaint is a 100 dollars seems kinda high but I guess compared to other resources it isnt that bad. From what ive seen, in terms of quality their bio>gc>phys>orgo. But I pretty much like most what ive seen so far. Id call these videos good supplement to a review, but not a replacement for TBR. Id say jco>wikki>khan. Although I dunno about chads. ask any questions if you're curious about these videos.