CFAI: Sample vs Mock

For those who have done them all - overall which are harder and which are more helpful? I’ve done sample I and II and I think I am going to dive into III shortly here, from what I hear it is difficult so wish me luck.

I haven’t done #3 yet, but i hear its pretty bad.

#3 Ethics is tough and so is FI

yea I keep trying not to read the post about it on here, but from what I have seen sounds pretty hard.

i breezed through other 3 item sets (made 1 stupid mistkae in econ) - 66%,100%,100%. but first 2 WAS HORRID.

stop scaring me damm!t