As long as the current type of itemisation continues, getting spirit on gear is usually a very bad idea.
Meaning that gear is "int/spi/dmg + 2 out of haste/hit/crit/spi(/mp5)", and getting spirit on gear means losing a DPS stat.
Next up, Student of the Mind is a terrible talent in terms of power. Sure, it's a good idea.
But it's 0.1% DPS/point, which is really bad. 3/3 SotM is worse than 1/3 Incineration, and Incineration is rather weak to begin with.
On itemization: In some slots (mostly bracers and boots), the best itemized item w/o spirit has hit which arcane doesn't need and there's an ilvl 226 piece with spirit. These pieces with spirit seem to be best in slot for arcane ( and .
Is there a better talent that actually increases dps than SotM? To me, it seems the best of a bad lot unless you want to start sticking points in frost (also a possibility, but with no increase on single target boss dps unless I'm missing something).