The only times I have felt weaker as a Summoner are when I am farming fates on my own and when I am a dps who has to take out boss adds QUICKLY.

Lets start with fates, if I am not in a group that fate mobs are hit or miss for me. If I get to the fate before the bulk of the fate farmers arrive I will do well. If I arrive mid way I am screwed. However, if there is only one fate boss or a main fate boss then all is well.

Next, dps as a summoner can be tricky. I don't have a problem with main bosses or regular pulls, but it is those tricky timed adds with the bosses that hurt me. I have to lay a foundation to kill adds. I have to set up my DoTs, use Bane, and spam tri-disaster (which is slow). Then I have to WAIT for the damage to happen. Doesn't play out too well with the boss adds in Aurum Vale. I can use sic, but the pets take too much time moving from the boss to the adds. Then I have to deal with players who get upset because I can't put out like a black mage or bard.