Got this for my first M4 ever back when I was 16. Yes it holds a ton of bb's, and yes it is good for suppressing. The downside is that you have to tilt the mag, and therefore the gun, to reload the upper part of the mag. And in the midst of a heated battle you may end up doing this a lot as you may not load as many bb's as you think. Plus this makes a lot of noise when moving around too. I don't hate this mag, it's just that it's not for me, but if you want to give your M4 that cool factor, this is definitely it.