Str has proven to be more effective but everyone cries about it so. Less tears w/ criticals but I don't think its worth it without an avalon.
There is a video on YouTube strength comes out on top but as other people said its easier to sneak in rooms but if you want to do more damage strength.
No one can lie that crit looks cooler tho, with all the big damage points and what not, especially with assassin
STR is better ofc because CRI is by chance. For example If you have 10 CRI then there is a 1%chance you'll land a critical attack and it might not even be that much damage. Plus its hard to get cri unless you get clothes such as the Fox ninja shirt but that costs RC. While most STR items can be bought with carats such as the Lead Gloves(3 STR 2 SPD(I think)) and the Green shrapnel(3 STR)
if you go into a room with high str your a *** and everyone knows it you go into a room and use high crit your less of a *** and less people know
From a neutral stand point, str reigns supreme just cus it can kill way faster more efficiently since it does not rely on chance. However like everyone else said, you can sneak crit in and the whine will be less.