beast trainer is alright... def worth the effort to get it since its not a class d hero and u can only have 1 beast trainer in a party.. kick ass aoe is what shes good for. I would say artillery man is much better for aoe, he is just fucking kick ass!
My aoe team consists of my shammy as my main (the spell is not particulary damaging but patches made it stronger) beast trainer, witch, artillery. Pvp they r great assets. Monks r must for pvp they r just taht godly. Shammy not quite, 2 of them would make ur front row really really firm. and with 4 melee tankers ur front row won't fall usually. i have yet to try out excerist and any other ones pass witch...