I was a SCH but now am a WHM, and gotta say, I LOVE WHM much, much more. Threat and Mana management are very important, and I have to constantly think all the time-- is my Medica going to be enough to top people off after this? Should I Cure 3 instead? Should I stoneskin Tank now--will there be enough time, or should I just pre-Cure 2? Like someone said in a comment: playing WHM is like playing chess. Knowing when to save/use Shroud, when to NOT use Regen, knowing how to plan your movements, pop your CDs... Beyond their seemingly "simple and straightforward" toolset, WHM is actually hard to master.

That said, I always love and appreciate an amazing SCH who shields and micros his fairy and pops CS every now and then.