The AMPS for the different classes will also come in play. It might be so that the Spellslinger have better response to the AMPs than the Esper making it a better healer at higher lvls. Of course i am only speculating here but I think that if we are gonna discuss who's better than the other we need to look at the whole picture. Not to mention tiering your abilities. We have seen little or none tooltips on Teir 8 for the different classes.