I've only really used pulse lasers on big ships, with big PDist's, but I've never really found a need to use Efficient with pulse-lasers.
I've found the most useful thing to do with them, for PvE, is to fit a pair of pulse-turrets, mod' 'em both for long-range and then apply the Emissive XFX to one and the Scramble Spectrum XFX to the other then just let them do their own thing.
They don't do a great deal of damage but they do reach out and touch enemy ships, prevent them from going dark and cause them problems.