With 3 points in summoning, my totems were each hitting for about 20 damage or so, on Classic.
The Totem-attack is considered aoe for terms of hitting clumped enemies, can be enchanted with spells to increase their survivability (Fortify), etc.
With three fire based totems, my summoner was pulling pretty high DPS, with the summons grinding through the target's magic shields and into their health, lighting them on fire to boot.
And that was at level 3-4, the totems alone were grinding away foes.
