Originally Posted by
Sheep
First of all, 2 crit should be equal to 1% amp. to find out how much amp is worth how much base attack, multiply your attack by 0.01 (1%) that's how much attack is worth 1% amp.
so, let's say you have 960 attack. 1% amp would give you 9.6 attack, which is the same thing as 2 crit.
Now that you have this knowledge, there shouldn't be any confusion over what item is better than what.
But remember, it isn't smart to just get as much crit as possible, while sacrificing your attack, because it's very important to do decent damage for your dps skills. Defense is generally defends against attack better than your attack can pierce low defense. For example, it would be smarter to choose 60 defense over 4% amp, unless your attack and amp is considerably low. If you chose the 4 amp over the 60 defense, the damage difference would be lower than the damage an enemy would do on you if you had the higher defense.
So, basically, 10 defense is equal to almost 1% amp.
Just multiply the gained defense by 0.75 and compare that to the total gained attack of the amp. go with whichever is highest.