ok, let's just disregard the comment about 5% extra crit for 4 shamans..
A boomer as of NOW is a kickass DPS'er, and with all the changes coming in WotLK they're going to be even better.
Anyways, the point is that you can't stack totems and buffs in wotlk. And yeah, 4 shamans with 5% more crit MORE than makes up for any
imaginable DPS loss.