I have tried both, and I can tell you that I loved both just the same. Both have their advantages, and their disadvantages. In terms of athletic performance they are very similar. Cardarine has the advantage of a longer half life, so you can take it just once per day. However, it does not have the additional benefits of SR9009, such as the lowering of blood sugar and increasing of insulin sensitivity. On the other hand, SR9009 needs to be taken several times per day for optimal results, and many times I found that very inconvenient. It is definitely worth giving both of them a try, and seeing by yourself which one is best.