They are very good yes..


I did some calculations to get a better feel for their output..
Assuming 4 shammies and average 1000 dmg per tick..
20 seconds = 10 ticks..

1000 * 10 * 4 = 40k damage total, on each target.. it's pretty nice.

On a single target it's roughly 2000 dps. So basically, against meelee, it's equivalent to 1 dps player going full out.