#2 is my favourite overall, which looks like a popular opinion.
The others aren't awful, but they have little details I don't care for:
#1 is my runners-up, but her expression doesn't look combat-ready; I'll probably use her for a future run where my IMP focuses on non-combat skills
#3 is probably my least favourite, with neither a portrait nor model that appeals to me
#4 is a great portrait, but the model could use some flair, or at least differently coloured highlight somewhere
#5 is just too milquetoast to me, especially in combination with the whitebread voice
#6 is actually pretty neat; I just need to find a character concept that fits it
I think that's overly harsh. The IMP has to be generic to fit whatever concept the player has for it (and many players use it as a self-insert). Any personality the devs include could conflict with what the player had in mind. I think they erred a bit too far on the side of caution, compared to JA2's IMPs, but I don't think this decision was due to laziness or just not caring.