Popularity of Spriest vs Boomy?

[MikePW]

For you warmane vets - which class seems to be the more represented between Shadow Priest and Balance Druid?

Torn between the 2 on the new frostmourne server and would honestly prefer playing the less represented one. :)

[Kovachut]

I don't remember whether boomie was less represented, but I can guarantee you that if you pick spriest you will have a solid spot in every raid.

In Naxx 25, spriests are responsible to mind control the adds in the Instructor boss fight.
In Ulduar, you'd be especially wanted in Algalon due to the amazing synergy between Bing Bang and Disperse.

[edit] Whether you pick boomie or spriest, both are solid options, since in the Naxx and Ulduar phases casters are more valuable than melees. This is especially true in Ulduar, where you have a handful of bosses, which create optimal conditions for ranged - Hodir (only magic users benefit from the fire), Thorim (too many melees = death from chain lightning), Mimiron (it's better to have too many rdps who would do damage to the head than too many melees, who won't reach it), Vezax (ranged do more dps due to the puddles), Algalon and Yogg (you can stand relatively close to the portals and maximise your damage output).