Pros:
1) No equipment needed aside from a good pair of shoes, and maybe some floor mats. You do not need dumbbells, a chin-up bar, or anything else. You do want to have or get a good pair of cross-training shoes though. A lot of people wear running shoes doing this and have lots of issues with pain or twisting their ankles. Running shoes are good for landing, but not plyometrics and lateral movements. Running shoes do not have the lateral stability to hold up when doing repetitive plyo exercises.
2) The workouts are relatively short. In month 1 they are all under 45 min, and in month 2 they are all under an hour.
3) The 60-day duration. I have done P90x multiple times and doing the same workouts for that long a time just gets boring. This is the perfect amount of time for a DVD workout series to last, and then you can decide to either re-do it or move on to another one be it P90x, P90x2 (also 90-day workouts but has different workouts in each month), or the even more advanced program, Insanity Asylum.
3) You cannot outgrow it. As you get in better shape you can go faster and take fewer breaks so it should never get easy.
Cons:
1) This is not really a program for beginners. Even the people in the videos have a hard time keeping up and have to stop and take breaks. If you have never worked out before or have gotten out of shape after a long layoff, I would suggest easing your way into this. Yes, you can do the moves slower and take more breaks when you first start out, but there is no modifier in the cast, and unless you have done Insanity Max-30, you will probably not be able to figure out how to modify the moves to make them easier like you can with other programs.
2) It is a very high impact. You are jumping and doing a lot of side-to-side movements in every workout, so if you have severe knee and/or back issues this is probably not the workout for you.
3) If you like to lift weights you will probably need to sub out either the recovery workout day or the rest day to do some upper body lifting. With all the squats and jumping you will be doing in Insanity you will probably not have to do much of a leg workout, but for people who can't go without lifting Insanity itself may not be enough.
On Amazon, the price. $144 is way too much, and I have heard about some of the "third-party" sellers selling faked bootlegged copies. If you are going to purchase on Amazon make sure it is being fulfilled by Beachbody which is the actual company that makes it.
Ultimately the best workout for you is going to be the one that you can stick with. Insanity is a good, but hard program that works if you do it. Like any workout, how well your results will be are going to depend not only on doing the workouts as hard as you can but also in large part on how you eat. Insanity does have a good nutrition guide to use as a base, but you may need to adjust your caloric intake to get the best results (and for many people that means eating more calories because the workouts are so intense). The main thing is you have to be following some kind of nutrition plan because if you are eating like crap, or on the other end of the spectrum not eating enough, the program will not give you anything like the results of the people in the infomercial.