Any barrel will work good, but between 14'' and 18'' is fine.
Strengths:
Bright fill, thick, hard to wipe, no dimples
Weaknesses:
Ocassional chop
Price a little heavy
Review:
I've shot many kinds of paint before, and none have had the neon-green fill I had with Steel. Very thick and juicy fill. Hard to bounce when hit by it, and doesn't curve alot. When you buy a case, request neon-green fill if you want to, because it's EXTREMELY hard to even wipe the fill. Though some WILL bounce, even on hard surfaces.
Conclusion:
Buy it if you want to make sure someone was hit. Recommended for rec-play only, not hyperball, unless it's practice.