Completely disagree to suggestions of wearing a summon like a suit of armour - people need to stop imagining this, it wont work and it does not fit the theme for the summoner at all.

I do agree with Dyvid - While I wouldn't usually look at outside influences for the FF series summoner the timed Summon would fit quite nicely to how Summons in most FF games are single attack/temporary party members and allow/encourage quick switching between the Egis - obvious MP cost reductions would be a necessity depending on the timer of each pet, or maybe a firecaster style proc would work?

Honestly, summoner is fun and effective - sure i'd love more burst to be a little more viable in a wider range of fights but that doesn't mean the class needs a re-design, a few tweaks to recast timers for our heavy hitting abilities would balance and keep it fair. A firestarter/Cure2 style proc would work wonders on Summoners for either resetting X abilities recast or giving free cast of X Egi.