I believe I recall you being 18 years old. My advice is to wait until you are a bit older before using these types of products.
Here is a good read for you:
If I am mistaken and you aren't under 21 or you are going to ignore the above advice......
They are both quality products with good reviews.
I am obviously a huge fan of Mass FX.
There are some reviews here on AM that can be found easily.
Here are some Mass FX reviews I snagged real quick from some other forums...
Reviewer: Deep Goat
"This stuff is awesome. Makes you want to go to the gym from the moment you wake up, and when you get there you feel like you can rip the place up. Big appetite (and not just for food...) and sound sleep really help. I was also taking pre-workout supp and creatine so hard to say how much effect this has directly on strength and size, but cos you work so hard on this and eat so much you cant help but get bigger. Good stuff. Recommended."
"Bought these 2 over 7 weeks ago and did an 6 week course, This is a very good product noticed extremely HARD muscle tone, on training days and on none training days. good weight and strenght gains, increased in weight from 86.7KG to 89.7KG + 3KGs. Strengh went up by about 15-20% and was recovering much quicker. the Pump is a little mental as your muscles are rock hard already and they really do feel like they are going to rip through your skin. Overall 5 Stars does what it says on the tin. Overall Look is bigger, Tonner & fuller look. im currently shredding down on and a good Diet to see the results will post on once Done."
"Took this after a friend recommended and haven't regreted it, noticed huge gains in strength and size, on my second cycle of it, have combined it with maximuscle cyclone and promax, i'm also eating a high protein diet. As for gains my bench has gone up by 10KG, squat has gone up by 20KG. Will be taking it again. IT does exactly what it does on the box."
At the bottom is a few from facebook: http://www.athleticxtreme.com/products/mass-fx#reviews
The Mass FX/ stack is one of the best available in my opinion.
Good Luck with your training and reaching your goals.
(I still highly advise to not use any if you are under 21.)