I use a SP1with a ,18'' evil barrel, double finger trigger, wire stock ,bipod, pure energy carbon fiber tank and a Dye Rotor.
Strengths:
Fast,easy cleaning,look and you can make it feed faster.
Weaknesses:
None.
Review:
It is awesome. You can drop it in water when it's on and it will still run, you drop it and it well not break and you can change the color to mach your i4 and 3's, dye put a lot of work to make a hopper that is the best and they nailed it.