You're losing out on -1 Parry as you indicated above.

Most people say that -1 Parry is more in conform to what your role is in a battle: To tank and take the least possible damage.

Min/Maxers will tell you that going and putting Crit only increases your output in threat and damage and as Threat on a single target is not hard to do in the game, there seems to be little to no point to the crit increase. Parry, however, will decrease your damage, even if it's only one point.

If you wanna maximize your mitigation: you're hurting yourself by going with DD stats. It comes to what you want to do though. If your party is fine with it, then go for it. 57 Crit won't really do 'that' much to your output in DPS or threat really.

Survival is always a preferred method. And the Det you lose decreases the healing potential done to you. Just remember that.