Not Insanity but I did try P90x and I after watching the videos they are about the same thing. While I thought I was in pretty decent shape after the chest and back workout I felt like I had been in a car accident. They are definitely a great addition to a routine if you don't like a traditional HIIT workout.

Also bought a P90x set off craigslist for $20, sure you can find the discs for cheap.