I believe this has been posted in a different thread, but Monks are better healers overall. They are best at single healing, Ritualists are better at party healing. Monks get the benefit of Divine Favour, where Ritualists do not.
I'm not sure about the power of an Elementalist vs the Ritualist. However, someone else (I can't remember the name) has posted a Ritualist doing over 400 damage.
I'm a new Ritualist/Necro (20th level but still new to the class) and I've seen spell descriptions stating a spell that does X amount of damage to foes in an area near spirits. The damage is multiplied by the number of spirits (upto 5 I think). Place spirits around an area (not clumpped together) and monsters that are drawn into the area, then cast that spell (I don't know the spell name) and damage to those monsters near the the spirits. The spirits themselves do their thing (damage, protection, heal, etc.) So, basically a Ritualist can to some very good healing and do some nasty damage.
I do agree with Markaedw, their animation of attacking is slow. Its fun to watch though. The twists of the body and having the Ritualist look upside down at his/her foe and blast them with a wand or staff.
Does anyone know if that animation means that if you are hit while attacking, your whole body is vulnerable to the attack? I mean everyone else is attacked mostly on the body, but a Ritualist sticks his/her head forward and has their body basically horizontal to the ground. So does that mean that your head, body and legs are all subject to being hit by a basic attack?