I'm playing 4x crusaders. They can do t4 rifts, but t3 is usually a cakewalk. Strangely they are more fun to play because they move slower and it makes it easier to multibox.
I'm also trying out 4x WD's. Like Ellay said, 1/2 the pets stand around doing nothing. But I did notice if you spec each guy into a different Big Bad Voodoo rune, it stacks. So when I pop it, my sheet dps goes up to like 1.4 mil from like 600k.
The downside to the WD pet build is definitely the fact that all your pets can't reach the mobs. So you get your little voodoo guys blocking your gargantuans that you just popped. But, some mobs will teleport of fear you around, so you're not always safe with the pets blocking you.
The other downside is your need some really specific gear to make the most out of the WD pet build.
The crusaders are a lot of fun. I really just need a few more specific drops. This is a link to my main crusader: http://us.battle.net/d3/en/profile/K.../hero/44419267