So my respect bill is 30 gold now at level 38 lol since i tried all these builds. In the end i settled with POM flamestrike, heavy into arcane and some fire build. Reason being, shatter build is great but ite just way too much work especially when you pull bigger groups. Crits supposed to offset mana use but i didnt reallly notice a difference. With heavy arcane its simple....pom>flamestrike>AE and throw CoC here and there. Also i notice the mana pool difference way more than when i went shatter build with crits. By the time i POM flamestrike and AE everything was dead. With constant novas it was a pain in the butt especially since even if you really do more damage its still hard to pull more mobs than arcane due to damage taken. Just my 2c. Try them all.