anything that can carry dual heavies can use quads

Thanks for the info

Yep... cuz the 3 piece Borg set will have it in Season 7... by default.

I usually get 60 to 62 on AUX power and the EPS power transfer ability as an engineer will help.

Oh, Quad Cannons can be slotted I believe: http://www.stowiki.org/Quad_Cannons

I don't know if this has changed since the patch, but the Quad Cannons (phaser) are limited to Escorts and Dreadnoughts and the Heavy Destroyer (the Chimera) only, at least according to the Wiki (which is sometimes out of date, I know). I take my Quad Cannons to every escort I use, but I haven't been able to use them on a non-escort.

Maybe they'll update the Vesta to use it, but since it's ostensibly a science or science-like ship I doubt they'll allow it.

Which non-escort non-dreadnought did you try them on Fed side? The only other ship types that I can think of that you didn't list that can take duals Fed side are fighters and maybe the Atrox.