Most CIEM have the dynamics and transient response covered well enough to handle EQ, I would take an average CIEM before a slightly better run of the mill over-ear any day.
Besides, there are no freq. response charts and the last thing I trust is word of mouth when people jump a bandwagon and many people spout he-said-she-said as first hand information.
OK, thanks for telling us how you feel. I'm not sure how it relates to the questions BBEG was asking though.... he said he thinks he likes neutral but has never really heard a good example of a V-shaped sound signature. Doesn't it make sense for him to investigate what he really likes prior to making a commitment with a custom IEM?