4 ranks in ARMOR CRUSH or 3 in CRUSH and 2 in REINFORCEMENT

[Gnomad]

Rank 3 -> 4 in CRUSH: 50 points
Rank 0 -> 2 in REINFORCE: 50 points

I'm leaning towards the second, because I don't think I get hit hard enough to justify the extra rank in Crush.

[Archigeek]

Not a fan of reinforcement. It never really seems to come into play in such a way that it's important, unlike crush which might be a life or death thing. I would take a close look at what you hunt too. Crush isn't always the best one to pick of the three fittings. Also, what type of armor are you using? If it's padded/warding, your crush/slash/puncture ranks are going to be penalized, but reinforcement and support will not.

Personally I find slash and support to be the most useful, but that has a lot to do with where I hunt.