for the first one i dont really like the square in the top right corner but i like the tech stuff
i dont really like the bg for the 2nd one cuz its kinda plain imo and i couldnt see the render until i look closely at it
for teh 3rd one i cant find anything wrong with it but a border is always a good finishing touch
the 4th one looks too plain and i dont really like but grey stuff over the
middle guy
the render looks weird in the 5th one...wheres his ear
and the last one the bg looks 10/10 but the render isnt the best