trade off, everyone play there way.
Big guns skill high + mini gun + lots of lead down range = no need for crits?
Small guns + sneaky = needs more crits.
no, I do not have that mod, seen it though.
The Vault http://fallout.wikia.com/wiki/Critical_Chance of which weapons that have the best critical multipliers. It also has the formula for how it's determined. Basically, 10 luck seems to double the chance compared to 5.