As a summoner, one of the changes in a recent patch was one of the first changes for the positive the job has seen in a long time.
The change is that in campaign, any AoE buff hits everyone in range with tags on.
12 people hit with a Healing Ruby II. And I was not in a party.
14 people hit with Ecliptic Growl.
The obvious advantage is that the exp a summoner can gain is greatly increased. All of these count as a buff to a non-party member, which is 10 per buff, max of 300. Plus, I think it counts as a self buff, which is 20 per buff, cap of 150. So while avatar damage will never quite reach that of a heavy DD class, especially in a longer fight where MP becomes an issue, there are ways to even it out.
From this Campaign Battle, I got.
This is solo. Summoner is a great job for solo exp in campaign now. Sub White Mage, and you can even raise/reraise.
*grins*
-pyra