Look at and compare the ingredients and see if you get more bang for your buck one way or the other.
I'd also read a few logs and reviews on each and go with what you feel is the best.
Most important thing is DIET!!!
If you don't have your diet right you'll be pissing your money away and don't get it right just for the cycle get it right, keep it right, then run your cycle. You should see way better results like that.
What's your diet and workouts look like right now??