Both of these compounds are quite similar in terms of fat loss and properties, but there are downsides to each of them:
1. SR9009 has such additional benefits as more pronounced fat loss even when not exercising, and its ability to lower blood sugar levels.
2. Cardarine has a longer half life, so you can dose it just once per day, which is not the case with SR9009. Therefore, cardarine is more convenient in terms of practicality
3. Cardarine is cheaper.
So it is basically up to you - just decide what will be less of a burdain for you