I do use them, but sparingly. They are generally inferior to beams/kinetics in DPS. They do have some advantages:
1) First strike. They fire first, so have a chance to take out some of the enemy ships before they even fire.
2) Map salvo: yes, you said to ignore it, but you really shouldn't. You can easily create a fast fleet that can dart in, salvo an enemy fleet, then dart out of range, repeatedly.