Mo/E? i'm one, haha. the only difference between getting Mo/E and E/Mo are:
1. E/Mo gets energy storage, which increases energy capacity, while Mo/E gets divine favor, which is kinda useless unless your build is a full time healer.
2. E/Mo gets to use Elementalist runes, while Mo/E gets monk runes. (http://www.gwonline.net/page.php?p=112)
3. different sets of armor. elementalist gets different sets of armor that has resistance to a particular element. they also get headgears that have +1 bonus to any one attribute. monks get head paints that have +1 to monk attributes.
i used to regret picking Mo/E, since i hardly use my divine favor at all, and extra energy would mean more nuking with my spells, but i don't anymore. being a monk primary, i get to use monk runes, and with a Rune of Superior Smiting Prayers, i have 16 in that attribute(12 max, +1 from head paint, +3 from rune), and i totally rape undead mobs.
i'm not exaggerating though. in the Gates of Kryta and D'alessio Seaboard missions, most of the monsters are undead. my smiting prayers made them really easy. i finished both with just 1 healer henchman, just the 2 of us.
whoa... You are a ---- blardy uber monk, would really wanna party with u in a mission