no it doesnt increase your other tanking stats, which is part of the reason res isnt preferred.
res lowers crits taken, and crit damage taken. if your already uncrittable, then the -crit damage taken is useless. it takes more res than defense to lower your crit rate, and that only effects crits, while defense will help your avoidance stats a little.
all in all, only take res if you have nothing else better to use really. while you can be uncrittable, if your avoiding less attacks you will be taking more damage.